WO2023238941A1 - Hot dip-coated steel sheet - Google Patents
Hot dip-coated steel sheet Download PDFInfo
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- WO2023238941A1 WO2023238941A1 PCT/JP2023/021579 JP2023021579W WO2023238941A1 WO 2023238941 A1 WO2023238941 A1 WO 2023238941A1 JP 2023021579 W JP2023021579 W JP 2023021579W WO 2023238941 A1 WO2023238941 A1 WO 2023238941A1
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Images
Classifications
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C18/00—Alloys based on zinc
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C18/00—Alloys based on zinc
- C22C18/04—Alloys based on zinc with aluminium as the next major constituent
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
- C23C2/04—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
- C23C2/06—Zinc or cadmium or alloys based thereon
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
- C23C2/14—Removing excess of molten coatings; Controlling or regulating the coating thickness
- C23C2/16—Removing excess of molten coatings; Controlling or regulating the coating thickness using fluids under pressure, e.g. air knives
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
- C23C2/26—After-treatment
Definitions
- the present invention relates to hot-dip galvanized steel sheets. This application claims priority based on Japanese Patent Application No. 2022-094358 filed in Japan on June 10, 2022, the contents of which are incorporated herein.
- Hot-dip plated steel sheets have excellent corrosion resistance, and among them, Zn-Al-Mg hot-dip plated steel sheets have particularly excellent corrosion resistance.
- Such hot-dip plated steel sheets are widely used in various manufacturing industries such as building materials, home appliances, and automobile fields, and their usage has been increasing in recent years.
- Patent Document 1 discloses a Zn-Al-Mg hot-dip galvanized steel sheet having a fine texture and a satin-like appearance with many smooth glossy areas, that is, a large number of white areas per unit area, and a glossy surface.
- a Zn-Al-Mg hot-dip galvanized steel sheet is described that has a good satin-like appearance with a large area ratio.
- Patent Document 1 describes that the unfavorable satin finish state is a state in which irregular white parts and circular glossy parts coexist and exhibit a surface appearance dotted on the surface. There is.
- Patent Document 4 discloses a highly corrosion-resistant hot-dip galvanized steel sheet in which the overall gloss of the plating layer is increased and the appearance uniformity is improved by refining the ternary eutectic structure of Al/MgZn 2 /Zn. is listed.
- the present invention has been made in view of the above circumstances, and provides a hot-dip plated steel sheet that can display letters, designs, etc. on the surface of the plated layer, has excellent durability, and is also excellent in corrosion resistance. That is the issue.
- the gist of the invention is as follows. [1] Comprising a steel plate and a hot-dip plating layer formed on the surface of the steel plate,
- the hot-dip plating layer has an average composition of Al: 5 to 22% by mass, Mg: 1.0 to 10% by mass, and the remainder contains Zn and impurities,
- the hot-dip plating layer has a pattern part and a non-pattern part,
- the pattern portion and the non-pattern portion each include one or two of a first region and a second region obtained by the following measurement method,
- a hot-dip plated steel sheet characterized in that the absolute value of the difference between the area ratio of the first region in the pattern part and the area ratio of the first region in the non-pattern part is 30% or more.
- the thickness of the hot-dip plating layer is t, and a cross section of 1 to 5 mm square parallel to the surface is exposed at any position of 3t/4, t/2 or t/4 from the surface of the hot-dip plating layer. Then, virtual lattice lines were drawn at 0.5 mm intervals on each of the above-mentioned cross sections, and a ternary eutectic structure of [Zn phase] and [Al/MgZn 2 /Zn] was formed in a plurality of regions partitioned by the virtual lattice lines.
- the area where the ratio (B/A (%)) of the area fraction B of [Zn phase] to the total area fraction A of ] is 20% or more is defined as the first region, and the ratio (B/A (%)) The region where the difference is less than 20% is defined as the second region.
- the hot-dip plating layer has an average composition of Al: 5 to 22% by mass, Mg: 1.0 to 10% by mass, and the remainder contains Zn and impurities, Furthermore, it contains one or two selected from the group consisting of Group A and Group B below,
- the hot-dip plating layer has a pattern part and a non-pattern part, The pattern portion and the non-pattern portion each include one or two of a first region and a second region obtained by the following measurement method, A hot-dip plated steel sheet, characterized in that the absolute value of the difference between the area ratio of the first region in the pattern part and the area ratio of the first region in the non-pattern part is 30% or more.
- Group A Si: 0.0001 to 2% by mass
- Group B Any one or two of Ni, Ti, Zr, Sr, Fe, Sb, Pb, Sn, Ca, Co, Mn, P, B, Bi, Cr, Sc, Y, REM, Hf, and C 0.0001 to 2% by mass of seeds or more in total
- the thickness of the hot-dip plating layer is t, and a cross section of 1 to 5 mm square parallel to the surface is exposed at any position of 3t/4, t/2 or t/4 from the surface of the hot-dip plating layer.
- the pattern portion is arranged so as to have a shape of any one of a straight line portion, a curved portion, a dotted portion, a figure, a number, a symbol, or a character, or a combination of two or more of these.
- a hot-dip plated steel sheet that can display characters, designs, etc. on the surface of the hot-dip plated layer, has excellent durability, and is also excellent in corrosion resistance.
- FIG. 1 is a schematic cross-sectional view illustrating a cross section (exposed surface) for measuring the plating structure of a hot-dip coating layer in a Zn-Al-Mg hot-dip galvanized steel sheet according to an embodiment of the present invention.
- FIG. 2 is a perspective view illustrating an exposed surface for measuring the plating structure of a hot-dip coating layer in a Zn-Al-Mg hot-dip galvanized steel sheet according to an embodiment of the present invention.
- FIG. 3 is a schematic diagram of a first region and a second region of a Zn-Al-Mg hot-dipped steel sheet according to an embodiment of the present invention.
- FIG. 4 is a schematic diagram of a metal plate having a lattice shape, which was used to transfer Zn powder onto the surface of the steel plate in the example.
- the present inventors investigated in detail the plating layer of a Zn-Al-Mg hot-dip plated steel sheet exhibiting a satin-like appearance.
- the satin-like appearance is caused by the coexistence of fine metallic luster parts exhibiting metallic luster and fine white parts exhibiting white color.
- the area fraction of the [Zn phase] on the surface of the plating layer was smaller than that in the white portion.
- the ratio of the [Zn phase] to the [ternary eutectic structure of Al/MgZn 2 /Zn] was higher than that in the metallic luster part. .
- the hot-dip plated steel sheet of this embodiment includes a steel plate 1 and a hot-dip plated layer 2 formed on the surface of the steel plate 1, and the hot-dip plated layer 2 has an average composition. , Al: 5 to 22% by mass, Mg: 1 to 10% by mass, and the remainder contains Zn and impurities.
- the non-patterned area 22 each include one or two of the first area A1 and the second area A2 obtained by the following measurement method, and the area ratio of the first area A1 in the patterned area 21 and the non-patterned area are
- This is a hot-dip plated steel sheet in which the absolute value of the difference from the area ratio of the first region A1 in the pattern portion 22 is 30% or more.
- the method of measuring the area ratio of the first region A1 in the pattern portion 21 and the area ratio of the first region A1 in the non-pattern portion 22 is as follows. 1 to 1 parallel to the surface 2a of the hot-dip plating layer 2 at any position 3t/4, t/2 or t/4 from the surface of the hot-dip plating layer 2, where the thickness of the hot-dip plating layer 2 is t. Expose a 5mm square cross section. Then, as illustrated in FIG.
- virtual grid lines are drawn at 0.5 mm intervals on each cross section, and [Zn phase] and [Al/MgZn 2 /Zn A region where the ratio (B/A (%)) of the area fraction B of the [Zn phase] to the total area fraction A of the ternary eutectic structure] is 20% or more is defined as the first region A1, and the ratio (B The area where /A (%)) is less than 20% is defined as a second area A2.
- the exposed surface for measurement illustrated in FIG. 3 is a 5 mm square. On the exposed surface, the number of regions defined by virtual grid lines is 100. If the pattern section is small and an exposed surface of 5 mm square cannot be formed inside the pattern section, the size of the exposed surface may be reduced.
- a plurality of exposed surfaces are formed, so that the total number of regions defined by the virtual grid lines is 100.
- the number of regions defined by virtual grid lines in one exposed surface is four. If a 1 mm square exposed surface is formed at 25 locations, the total number of regions defined by the virtual grid lines will be 100.
- the number of pattern parts may be two or more. In this case, the exposed surface for measurement may be formed in each of the plurality of pattern parts. If the pattern section is very narrow and the number of regions partitioned by the virtual grid lines cannot be set to 100, the intervals between the virtual grid lines may be narrowed.
- the interval between the virtual grid lines may be changed to a value of 0.2 mm or more and less than 0.5 mm.
- the number of regions (i.e., measurement points) defined by the virtual grid lines can be set to 100 within a very narrow pattern section.
- the distance between these exposed surfaces is made as small as possible.
- a plurality of exposed surfaces formed inside the pattern portion may be in contact with each other. Even when a plurality of exposed surfaces are formed inside the non-patterned portion, it is preferable that the distance between the plurality of exposed surfaces be as small as possible, and the plurality of exposed surfaces may be in contact with each other.
- the exposed surface formed inside the pattern part and the area ratio of the non-pattern part are measured. It is also preferable that the distance between the exposed surface and the exposed surface formed inside is as small as possible.
- a cross section of 1 to 5 mm square is exposed at any position of 3t/4 position, t/2 position, or t/4 position from the surface of hot-dip coating layer 2, and the cross section is
- virtual grid lines are drawn at intervals of .5 mm, a plurality of regions defined by the virtual grid lines are divided into either a first region A1 or a second region A2.
- the area of the [Zn phase] relative to the total area fraction A of the [Zn phase] and [ternary eutectic structure of Al/MgZn 2 /Zn] determines whether it is divided into the first region A1 or the second region A2. It is determined according to the ratio of fraction B (B/A (%)).
- the first area A1 is an area where the ratio (B/A (%)) is 20% or more. Since the ratio (B/A (%)) of the first area A1 is high, the areas in the hot-dip plating layer 2 that contain a large amount of the first area appear white or close to white when observed with the naked eye or under a microscope. appear.
- the second area A2 is an area where the ratio (B/A (%)) is less than 20%.
- the second area A2 has a low ratio (B/A (%)), so when observed with the naked eye or under a microscope, the hot-dip plating layer contains a large amount of the second area A2 and a small amount of the first area A1. It appears to have a metallic luster. Further, in areas where the first area A1 and the second area A2 coexist and the area ratio of the first area A1 is 30 to 70%, the appearance appears satin-like.
- the surface 2a of the hot-dip plating layer 2 appears white or nearly white, has a metallic luster, or has a satin finish.
- the pattern part 21 that constitutes these characters, etc. and the other non-pattern part 22. It would be good if it could be identified.
- the area ratio of the first region A1 in the pattern portion 21 and the area ratio of the first region A1 in the non-pattern portion 22 need only be different.
- the absolute value of the difference between the area ratio of the first area A1 in the pattern part 21 and the area ratio of the first area A1 in the non-pattern part 22 may be 95% or less, 90% or less, or 85% or less.
- the pattern portion 21 when the area ratio of the first region A1 in the pattern portion 21 is 75%, the pattern portion 21 appears white or a color close to white. Furthermore, when the area ratio of the first region A1 in the non-patterned portion 22 is 45% or less, it appears satin-like or has metallic luster. When the difference in area ratio of the first area A1 between the pattern section 21 and the non-pattern section 22 is 30% or more, the pattern section 21 and the non-pattern section 22 can be distinguished from each other due to such a difference in appearance.
- both the pattern section 21 and the non-pattern section 22 are Although it looks satin-like, since the area ratio of the first region A1 in the pattern section 21 is large, the pattern section 21 has a whiter appearance than the non-pattern section 22.
- the difference in area ratio of the first area A1 between the pattern section 21 and the non-pattern section 22 is 30% or more, the pattern section 21 and the non-pattern section 22 can be distinguished from each other due to such a difference in appearance.
- the pattern portion 21 when the first area A1 of the pattern portion 21 is 50%, the pattern portion 21 appears satin-like. Further, when the area ratio of the first region A1 in the non-patterned portion 22 is 20% or less, it appears to have metallic luster. When the difference in area ratio of the first area A1 between the pattern section 21 and the non-pattern section 22 is 30% or more, the pattern section 21 and the non-pattern section 22 can be distinguished from each other due to such a difference in appearance.
- the pattern part 21 and the non-pattern part 22 Since the appearance is different, the pattern portion 21 can be clearly identified. That is, in the visible light image of the surface 2a of the plating layer 2, the difference in hue, brightness, chroma, etc. between the pattern portion 21 and the non-pattern portion 22 becomes large, so that the pattern portion 21 and the non-pattern portion 22 become distinguishable. .
- the difference between the area ratio of the first area A1 in the pattern part 21 and the area ratio of the first area A1 in the non-pattern part 22 becomes less than 30% in absolute value, the appearance of the pattern part 21 and the non-pattern part 22 will change. There is no difference, and the pattern portion 21 cannot be clearly identified. That is, in the visible light image of the surface 2a of the plating layer 2, the difference in hue, brightness, chroma, etc. between the pattern portion 21 and the non-pattern portion 22 becomes small, so that the pattern portion 21 and the non-pattern portion 22 cannot be distinguished.
- the hot-dip plating layer according to this embodiment is formed by applying the hot-dip plating method described below to the steel plate.
- the average composition of the hot-dip plating layer is Al: 5 to 22% by mass, Mg: 1.0 to 10% by mass, and the balance includes Zn and impurities.
- the average composition contains Al: 5 to 22% by mass, Mg: 1.0 to 10% by mass, and the remainder consists of Zn and impurities.
- the hot-dip plating layer may contain one or two selected from the group consisting of Group A and Group B below.
- Group A Si: 0.0001 to 2% by mass
- Group B Any one or two of Ni, Ti, Zr, Sr, Fe, Sb, Pb, Sn, Ca, Co, Mn, P, B, Bi, Cr, Sc, Y, REM, Hf, and C 0.0001 to 2% by mass of seeds or more in total
- the Mg content is in the range of 1.0 to 10% by mass in terms of average composition. Mg is preferably included in order to improve corrosion resistance. If the content of Mg in the hot-dip plating layer is 1.0% by mass or more, the effect of improving corrosion resistance will be further enhanced. If it exceeds 10% by mass, dross generation in the plating bath becomes significant, making it difficult to stably produce hot-dip plated steel sheets. From the viewpoint of the balance between corrosion resistance and dross generation, the content of Mg is preferably 1.5% by mass or more, 2% by mass or more, or 4% by mass or more. From the viewpoint of the balance between corrosion resistance and dross generation, the Mg content is preferably 8% by mass or less, 7% by mass or less, or 6% by mass or less.
- Impurities include those that are unavoidably included in base metals such as zinc, and those that are included when steel is melted in a plating bath.
- the hot-dip plating layer containing Al, Mg, and Zn includes [Al phase] and [ternary eutectic structure of Al/Zn/MgZn 2 ]. It has a form in which the [Al phase] is included in the matrix of [ternary eutectic structure of Al/Zn/MgZn 2] . Furthermore, the matrix of [ternary eutectic structure of Al/Zn/MgZn 2] contains [MgZn 2 phase] and [Zn phase]. Moreover, when Si is added, [Mg 2 Si phase] may be included in the matrix of [ternary eutectic structure of Al/Zn/MgZn 2 ].
- This Al'' phase at high temperature normally appears separated into a fine Al phase and a fine Zn phase at room temperature.
- the Zn phase in the ternary eutectic structure dissolves a small amount of Al, and in some cases is a Zn solid solution containing a small amount of Mg.
- the MgZn two phase in the ternary eutectic structure is a metal that exists near Zn: about 84% by mass in the Zn-Mg binary equilibrium phase diagram. It is an intermediate compound phase.As can be seen from the phase diagram, each phase does not contain any other additive elements, or even if it does, it is considered to be in a very small amount, but the amount is clearly determined by normal analysis. Therefore, the ternary eutectic structure consisting of these three phases is herein referred to as [ternary eutectic structure of Al/Zn/MgZn 2 ].
- the [Al phase] is a phase that appears like an island with clear boundaries in the matrix of the above-mentioned ternary eutectic structure; This corresponds to the "Al" phase (which is an Al solid solution containing Zn and a small amount of Mg).
- the amount of dissolved Zn and Mg in this Al'' phase at high temperature differs depending on the Al and Mg concentrations in the plating bath.At room temperature, this Al'' phase at high temperature is usually composed of a fine Al phase and a fine Zn phase.
- a patterned portion and a non-patterned portion are formed on the surface of the hot-dip plating layer of this embodiment.
- the pattern portion be arranged to have a predetermined shape. Further, from the viewpoint of ensuring the visibility of the pattern section, the larger the size of the pattern section, the more preferable.
- the pattern portion has an artificial shape.
- the pattern portions are arranged in an intentional shape. It is preferable that the pattern portions are arranged to have a shape of any one of a straight line portion, a curved portion, a dot portion, a figure, a number, a symbol, or a character, or a combination of two or more of these.
- a string of characters, a string of numbers, a symbol, a mark, a diagram, a design drawing, or a combination thereof consisting of a pattern portion appears.
- the straight portions and curved portions in the pattern portion each have a length of 1 mm or more. By exhibiting these shapes, it can be said that the pattern portion was intentionally formed. It is preferable that the straight line portions and curved portions in the pattern portion have a width that can be visually recognized as described below, and each have a length of 1 mm or more.
- the dot portions in the pattern portion preferably have an equivalent circle diameter of 1 mm or more and less than 10 mm, and more preferably a plurality of dot portions are regularly arranged.
- the pattern portion is a figure, number, symbol, pattern, or character
- the shape of these can be visually recognized as described below. By showing such dimensions and shape, it can be said that the shape was intentionally formed.
- the non-pattern portion is an area other than the pattern portion. Even if a part of the pattern part is missing, such as a missing dot, it is acceptable as long as it can be recognized as a whole.
- the non-patterned portion may have a shape that borders the patterned portion.
- the surface of the hot-dip plating layer is arranged with any one of straight parts, curved parts, dotted parts, figures, numbers, symbols, or characters, or a combination of two or more of these, these areas can be made into a pattern part, and the other area can be made into a non-pattern part.
- This shape is intentionally or artificially formed by a manufacturing method described below, and is not naturally formed.
- the boundary between the pattern portion and the non-pattern portion can be recognized with the naked eye.
- the boundary between the pattern portion and the non-pattern portion may be determined from an enlarged image using an optical microscope, a magnifying glass, or the like.
- the pattern portion is preferably formed to a size that allows the presence of the pattern portion to be determined with the naked eye, under a magnifying glass, or under a microscope.
- the non-patterned portion is a region that occupies most of the hot-dip plating layer (the surface of the hot-dip plating layer).
- the pattern section is arranged within the non-pattern section.
- the pattern part has a shape in the non-pattern part of any one of a straight line part, a curved part, a figure, a dot part, a figure, a number, a symbol, or a character, or a combination of two or more of these.
- the area ratio occupied by the pattern part on the surface of the hot-dip plating layer is significantly smaller than that of the non-pattern part.
- the area ratio occupied by the pattern portion on the surface of the hot-dip plating layer is 30% or less, 25% or less, 20% or less, or 15% or less.
- the pattern part and the non-pattern part are regions formed on the surface of the hot-dip plating layer, and the pattern part and the non-pattern part each include one type of the first region and the second region. Or two types are included.
- the first region is a region where the ratio (B/A (%)) is 20% or more, areas in the hot-dip plating layer where the first region is large appear white or a color close to white.
- the second region has a ratio (B/A (%)) of less than 20%, areas in the hot-dip plating layer where the second region is large appear to have metallic luster. Further, in areas where the first area and the second area are dispersed and gathered together, and the area ratio of the first area is 30 to 70%, the appearance appears satin-like.
- the first area and the second area are determined as follows. Assuming the thickness of the hot-dip plating layer is t, at any position of 3t/4, t/2 or t/4 from the surface of the hot-dip plating layer, parallel to the surface 2a and 1 to 5 mm square in plan view.
- the hot-dip plating layer is cut out so that a square-shaped exposed surface 3, 4, or 5 is exposed. This forms an exposed surface (cross section) of 1 to 5 mm square parallel to the surface of the hot-dip plating layer.
- a region where the ratio (B/A (%)) is 20% or more is defined as a first region, and a region where the ratio (B/A (%)) is less than 20% is defined as a second region.
- the thickness of the hot-dip plating layer 2 formed on the steel plate 1 is t, and the positions 3t/4, t/2, or t/4 from the surface 2a of the hot-dip plating layer 2 are At any position, an exposed surface 3, 4, or 5 of 1 to 5 mm square is formed parallel to the surface.
- the shape of the exposed surface may be at least 1 mm square. In this case, by increasing the number of exposed surfaces, the area of the measurement region is secured.
- [Zn phase] is measured as [Zn phase] in a region where the equivalent circle diameter is 2.5 ⁇ m or more. Thereby, the Zn phase in the [ternary eutectic structure of Al/MgZn 2 /Zn] is distinguished from the [Zn phase].
- the pattern section includes a plurality of regions divided by virtual grid lines, and each region is classified as either a first region or a second region. Further, the non-pattern portion also includes a plurality of regions partitioned by virtual grid lines, and each region is classified as either a first region or a second region. That is, the pattern section may include only either the first area or the second area, or may include two types of the first area and the second area. Similarly, the non-pattern portion may include only either the first region or the second region, or may include two types, the first region and the second region.
- the pattern part and the non-pattern part can be distinguished. Become.
- the difference in area ratio is less than 30%, the difference between the area ratio of the first region in the pattern part and the area ratio of the first region in the non-pattern part is small, and the appearance of the pattern part and the non-pattern part are similar. This makes it difficult to identify the pattern part.
- the larger the difference in area ratio the better; it is more preferably 40% or more, and even more preferably 60% or more.
- the hot-dip plated steel sheet according to this embodiment may have a chemical conversion coating layer or a coating layer on the surface of the hot-dip plated layer.
- the type of the chemical conversion coating layer or coating layer is not particularly limited, and any known chemical conversion coating layer or coating layer can be used.
- the hot-dip galvanized steel sheet according to the first embodiment of the present invention has been described above.
- a hot-dipped steel plate according to a second embodiment of the present invention will be described.
- the hot-dip plated steel plate according to the second embodiment includes a steel plate and a hot-dip plated layer formed on the surface of the steel plate, and the average composition of the hot-dip plated layer is Al: 5 to 22% by mass, Mg: 1.
- the area that can include the entire 1.0 mm square is "an area larger than or equal to 1.0 mm square.” According to this characteristic point, the first portion and the second portion can be clearly identified with the naked eye. By forming the first portion and the second portion into arbitrary shapes, letters, designs, etc. can be displayed on the surface of the plating layer.
- the steel sheet is immersed in a hot-dip plating bath whose chemical components have been adjusted, thereby causing molten metal to adhere to the surface of the steel sheet.
- the steel plate is pulled out of the plating bath, and after controlling the amount of adhesion by gas wiping, the molten metal is solidified.
- [Al phase] is first formed, and then as the temperature of the molten metal decreases, [ternary eutectic structure of Al/Zn/MgZn 2 ] is formed.
- the present inventors have come to the knowledge that it crystallizes as a [Zn] phase. As a means to reduce the number of Zn nucleation points, it is possible to improve the surface cleanliness of the steel sheet that is the original sheet and to reduce as much as possible substances that can become Zn nucleation points.
- Zn in the liquid phase immediately before final solidification crystallizes as a fine Zn phase in the [ternary eutectic structure of Al/Zn/MgZn2 ] , and forms a coarse [ The Zn] phase is difficult to crystallize, and the surface of the hot-dip plating layer takes on a metallic luster appearance.
- a conceivable way to increase the number of Zn nucleation points is to increase the surface cleanliness of the steel plate and then arrange substances that can become Zn nucleation points in a predetermined pattern.
- the hot-dip plated steel sheet of this embodiment is treated to increase the cleanliness of the surface of the steel sheet, and then regions with low cleanliness are arranged in a predetermined pattern.
- the steel plate is immersed in a hot-dip plating bath, pulled out, and then cooled to solidify the hot-dip plating layer.
- a hot-rolled steel plate is manufactured, and if necessary, the hot-rolled plate is annealed. After pickling, cold rolling is performed to obtain a cold rolled sheet. After the cold-rolled sheet is degreased and washed with water, it is annealed (cold-rolled sheet annealing), and the annealed cold-rolled sheet is immersed in a hot-dip plating bath to form a hot-dip plating layer.
- the steel sheet is subjected to alkaline electrolytic cleaning, washed with pure water, and then dried under an inert atmosphere. Move on to the cold rolled plate annealing process.
- the thickness of the hot-dip plated layer in the patterned area does not decrease to the extent that the corrosion resistance deteriorates compared to the thickness of the hot-dipped plated layer in the non-patterned area. Therefore, the hot-dip plated steel sheet of this embodiment has excellent corrosion resistance.
- a hot-dip plated steel sheet that has high durability in the pattern portion and has suitable plating properties such as corrosion resistance.
- a roll with Zn powder adhered to a predetermined shape area is pressed against an annealed cold-rolled sheet with increased cleanliness, and the surface shape of the roll is changed to the annealed cold-rolled sheet.
- the surface of the hot-dip plating layer can be made into an intentional or artificial shape in the patterned area or non-patterned area, including straight parts, curved parts, dotted parts, figures, numbers, etc.
- the pattern portion can be arranged to have a shape that is either one of symbols or characters, or a combination of two or more of these.
- hot-dip-plated steel sheet No. 51 the composition of the hot-dip-plated layer was appropriate, and Zn powder was attached to the surface of the steel sheet before the hot-dip plating treatment.
- No. In hot-dip plated steel plate No. 51 the surface of the steel plate was insufficiently cleaned before Zn was attached. Therefore, No. In hot-dip plated steel sheet No. 51, the absolute value of the difference between the area ratio of the first region in the pattern part and the area ratio of the first region in the non-pattern part was less than 30%. This resulted in inferior identifiability.
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Abstract
The present invention employs a hot dip-coated steel sheet that comprises a hot dip-coated layer formed on a surface of a steel sheet. A pattern section and a non-pattern section are formed in the hot dip-coated layer. The pattern and non-pattern sections include a first region and a second region defined in the following, and the absolute value of the difference in the area percentage of the first region between the pattern and non-pattern sections is at least 30%. A cross-section parallel to the surface of the hot dip-coated layer and located at either one of positions of 3t/4, t/2, and t/4 from the surface is exposed. Then, virtual grid lines are drawn on each cross-section to divide the cross-section into a plurality of regions. A region, in which the ratio of the area fraction B of a [Zn phase] with respect to the total area fraction A of the [Zn phase] and a [ternary eutectic structure of Al/MgZn2/Zn] is at least 20%, is defined as the first region, and a region, in which said ratio is less than 20%, is defined as the second region.
Description
本発明は、溶融めっき鋼板に関する。
本願は、２０２２年６月１０日に、日本に出願された特願２０２２－０９４３５８号に基づき優先権を主張し、その内容をここに援用する。 The present invention relates to hot-dip galvanized steel sheets.
This application claims priority based on Japanese Patent Application No. 2022-094358 filed in Japan on June 10, 2022, the contents of which are incorporated herein.
本願は、２０２２年６月１０日に、日本に出願された特願２０２２－０９４３５８号に基づき優先権を主張し、その内容をここに援用する。 The present invention relates to hot-dip galvanized steel sheets.
This application claims priority based on Japanese Patent Application No. 2022-094358 filed in Japan on June 10, 2022, the contents of which are incorporated herein.
溶融めっき鋼板は、耐食性に優れており、その中でもＺｎ－Ａｌ－Ｍｇ系溶融めっき鋼板は、特に優れた耐食性を備えている。このような溶融めっき鋼板は、建材、家電、自動車分野等種々の製造業において広く使用されており、近年、その使用量が増加している。
Hot-dip plated steel sheets have excellent corrosion resistance, and among them, Zn-Al-Mg hot-dip plated steel sheets have particularly excellent corrosion resistance. Such hot-dip plated steel sheets are widely used in various manufacturing industries such as building materials, home appliances, and automobile fields, and their usage has been increasing in recent years.
ところで、溶融めっき鋼板の溶融めっき層の表面に、文字、デザイン画などを現すことを目的として、溶融めっき層に印刷や塗装などの工程を施すことにより、文字、デザイン画などを溶融めっき層の表面に現す場合がある。
By the way, for the purpose of making letters, designs, etc. appear on the surface of the hot-dip coating layer of a hot-dip-coated steel sheet, by applying processes such as printing or painting to the hot-dip coating layer, letters, designs, etc. can be printed on the hot-dip coating layer. It may appear on the surface.
しかし、溶融めっき層に印刷や塗装などの工程を行うと、文字やデザイン等を施すためのコストや時間が増大する問題がある。更に、印刷や塗装によって文字やデザイン等をめっき層の表面に現す場合は、需要者から高い支持を得ている金属光沢外観が失われるだけでなく、塗膜自体の経時劣化や塗膜の密着性の経時劣化の問題から、耐久性が劣り、時間とともに文字やデザイン等が消失してしまう恐れがある。また、インクをスタンプすることで文字やデザイン等をめっき層の表面に現す場合は、コストや時間は比較的抑えられるものの、インクによって、溶融めっき層の耐食性が低下する懸念がある。
However, when processes such as printing and painting are performed on the hot-dip plating layer, there is a problem in that the cost and time for applying letters, designs, etc. increase. Furthermore, when characters or designs are displayed on the surface of the plating layer by printing or painting, not only does the metallic luster appearance that is highly popular among customers be lost, but also the paint film itself deteriorates over time and the adhesion of the paint film deteriorates. Due to the problem of physical deterioration over time, durability is poor, and there is a risk that letters, designs, etc. may disappear over time. In addition, when stamping ink to display letters, designs, etc. on the surface of the plating layer, costs and time are relatively reduced, but there is a concern that the ink may reduce the corrosion resistance of the hot-dip plating layer.
下記特許文献に示されるように、Ｚｎ－Ａｌ－Ｍｇ系溶融めっき鋼板に対する様々な技術開発がなされているが、めっき層の表面に文字やデザイン等を現した場合にその耐久性を向上させる技術は知られていない。
As shown in the following patent documents, various technologies have been developed for Zn-Al-Mg hot-dip galvanized steel sheets, but there is a technology that improves the durability when letters, designs, etc. appear on the surface of the plating layer. is not known.
Ｚｎ－Ａｌ－Ｍｇ系溶融めっき鋼板に関し、Ｚｎ－Ａｌ－Ｍｇ系溶融めっき鋼板にみられる梨地状のめっき外観をより美麗とすることを目的とする従来技術は存在する。
With regard to Zn-Al-Mg hot-dip plated steel sheets, there is a conventional technology aimed at making the satin-like plating appearance seen in Zn-Al-Mg hot-dip plated steel sheets more beautiful.
例えば、特許文献１は、キメが細かく、かつ平滑な光沢部が多い梨地状の外観を有するＺｎ－Ａｌ－Ｍｇ系溶融めっき鋼板、すなわち、単位面積当たりの白色部の個数が多く、そして、光沢部の面積の割合が大きいという良好な梨地状の外観を有するＺｎ－Ａｌ－Ｍｇ系溶融めっき鋼板が記載されている。また、特許文献１においては、好ましくない梨地の状態を、不定形な白色部と円形状の光沢部とが混在して表面に点在した表面外観を呈している状態であることが記載されている。
For example, Patent Document 1 discloses a Zn-Al-Mg hot-dip galvanized steel sheet having a fine texture and a satin-like appearance with many smooth glossy areas, that is, a large number of white areas per unit area, and a glossy surface. A Zn-Al-Mg hot-dip galvanized steel sheet is described that has a good satin-like appearance with a large area ratio. Further, Patent Document 1 describes that the unfavorable satin finish state is a state in which irregular white parts and circular glossy parts coexist and exhibit a surface appearance dotted on the surface. There is.
また、特許文献２には、めっき層の厚さ方向断面において、めっき層と地鉄との界面からめっき表層の間にＡｌ晶が非存在である部分が、該断面の幅方向長さの１０％～５０％を占めることで、めっき外観を向上させたＺｎ－Ａｌ－Ｍｇ系めっき鋼板が記載されている。
Further, Patent Document 2 discloses that in a cross section in the thickness direction of a plating layer, a portion where no Al crystal exists between the interface between the plating layer and the base steel and the plating surface layer is 10 times the length in the width direction of the cross section. A Zn-Al-Mg based plated steel sheet is described in which the appearance of the coating is improved by accounting for % to 50%.
更に、特許文献３には、めっき鋼板表面の中心線平均粗さＲａが０．５～１．５μｍであり、ＰＰＩ（１インチ（２．５４ｃｍ）あたりに含まれる１．２７μｍ以上の大きさのピークの数）が１５０～３００であり、Ｐｃ（１ｃｍあたりに含まれる０．５μｍ以上の大きさのピークの数）がＰｃ≧ＰＰＩ／２．５４＋１０である成形性に優れた溶融亜鉛めっき鋼板が記載されている。
Furthermore, Patent Document 3 states that the centerline average roughness Ra of the plated steel plate surface is 0.5 to 1.5 μm, and that PPI (with a size of 1.27 μm or more included per inch (2.54 cm)) A hot-dip galvanized steel sheet with excellent formability, in which the number of peaks) is 150 to 300, and the Pc (number of peaks with a size of 0.5 μm or more included per 1 cm) is Pc≧PPI/2.54+10. Are listed.
更にまた、特許文献４は、Ａｌ／ＭｇＺｎ２／Ｚｎの三元共晶組織を微細化させることで、全体的にめっき層の光沢度が増し、外観均一性が向上した高耐食性溶融亜鉛めっき鋼板が記載されている。
Furthermore, Patent Document 4 discloses a highly corrosion-resistant hot-dip galvanized steel sheet in which the overall gloss of the plating layer is increased and the appearance uniformity is improved by refining the ternary eutectic structure of Al/MgZn 2 /Zn. is listed.
しかしながら、めっき層の表面に文字等を現した場合に、その耐久性を向上させ、かつ、耐食性を低下させないようにする技術は、従来から知られていなかった。
However, there has been no known technique for improving the durability and preventing the corrosion resistance from decreasing when characters or the like are displayed on the surface of the plating layer.
本発明は、上記事情に鑑みてなされたものであり、めっき層の表面に文字やデザイン等を現すことができ、それらの耐久性に優れ、また、耐食性にも優れた溶融めっき鋼板を提供することを課題とする。
The present invention has been made in view of the above circumstances, and provides a hot-dip plated steel sheet that can display letters, designs, etc. on the surface of the plated layer, has excellent durability, and is also excellent in corrosion resistance. That is the issue.
本発明の要旨は以下の通りである。
［１］ 鋼板と、前記鋼板の表面に形成された溶融めっき層と、を備え、
前記溶融めっき層は、平均組成で、Ａｌ：５～２２質量％、Ｍｇ：１．０～１０質量％を含有し、残部がＺｎおよび不純物を含み、
前記溶融めっき層に、パターン部と、非パターン部とがあり、
前記パターン部及び前記非パターン部は、それぞれ、下記の測定方法で得られる第１領域、第２領域のうちの１種または２種を含み、
前記パターン部における前記第１領域の面積率と、前記非パターン部における前記第１領域の面積率との差の絶対値が、３０％以上であることを特徴とする、溶融めっき鋼板。
［測定方法］
前記溶融めっき層の厚みをｔとして、前記溶融めっき層の表面から３ｔ／４位置、ｔ／２位置またはｔ／４位置のいずれかの位置において前記表面に平行な１～５ｍｍ四方の断面を露出させ、前記の各断面に０．５ｍｍ間隔で仮想格子線を描き、前記仮想格子線によって区画される複数の領域においてそれぞれ、〔Ｚｎ相〕および〔Ａｌ／ＭｇＺｎ２／Ｚｎの三元共晶組織〕の合計面積分率Ａに対する〔Ｚｎ相〕の面積分率Ｂの比率（Ｂ／Ａ（％））が２０％以上になる領域を前記第１領域とし、比率（Ｂ／Ａ（％））が２０％未満となる領域を第２領域とする。
［２］ 鋼板と、前記鋼板の表面に形成された溶融めっき層と、を備え、
前記溶融めっき層は、平均組成で、Ａｌ：５～２２質量％、Ｍｇ：１．０～１０質量％を含有し、残部がＺｎおよび不純物を含み、
さらに下記Ａ群、Ｂ群からなる群から選択される１種または２種を含有し、
前記溶融めっき層に、パターン部と、非パターン部とがあり、
前記パターン部及び前記非パターン部は、それぞれ、下記の測定方法で得られる第１領域、第２領域のうちの１種または２種を含み、
前記パターン部における前記第１領域の面積率と、前記非パターン部における前記第１領域の面積率との差の絶対値が、３０％以上であることを特徴とする、溶融めっき鋼板。
［Ａ群］Ｓｉ：０．０００１～２質量％
［Ｂ群］Ｎｉ、Ｔｉ、Ｚｒ、Ｓｒ、Ｆｅ、Ｓｂ、Ｐｂ、Ｓｎ、Ｃａ、Ｃｏ、Ｍｎ、Ｐ、Ｂ、Ｂｉ、Ｃｒ、Ｓｃ、Ｙ、ＲＥＭ、Ｈｆ、Ｃのいずれか１種または２種以上を、合計で０．０００１～２質量％
［測定方法］
前記溶融めっき層の厚みをｔとして、前記溶融めっき層の表面から３ｔ／４位置、ｔ／２位置またはｔ／４位置のいずれかの位置において前記表面に平行な１～５ｍｍ四方の断面を露出させ、前記の各断面に０．５ｍｍ間隔で仮想格子線を描き、前記仮想格子線によって区画される複数の領域においてそれぞれ、〔Ｚｎ相〕および〔Ａｌ／ＭｇＺｎ２／Ｚｎの三元共晶組織〕の合計面積分率Ａに対する〔Ｚｎ相〕の面積分率Ｂの比率（Ｂ／Ａ（％））が２０％以上になる領域を前記第１領域とし、比率（Ｂ／Ａ（％））が２０％未満となる領域を第２領域とする。
［３］ 前記パターン部が、直線部、曲線部、ドット部、図形、数字、記号若しくは文字のいずれか１種またはこれらのうちの２種以上を組合せた形状となるように配置されていることを特徴とする［１］または［２］に記載の溶融めっき鋼板。
［４］ 前記溶融めっき層の付着量が前記鋼板両面合計で３０～６００ｇ／ｍ２であることを特徴とする［１］～［３］の何れか一項に記載の溶融めっき鋼板。
［５］ 前記溶融めっき層が、質量％で、前記Ａ群を含有する平均組成を有する［２］～［４］の何れか一項に記載の溶融めっき鋼板。
［６］ 前記溶融めっき層が、質量％で、前記Ｂ群を含有する平均組成を有する［２］～［５］の何れか一項に記載の溶融めっき鋼板。 The gist of the invention is as follows.
[1] Comprising a steel plate and a hot-dip plating layer formed on the surface of the steel plate,
The hot-dip plating layer has an average composition of Al: 5 to 22% by mass, Mg: 1.0 to 10% by mass, and the remainder contains Zn and impurities,
The hot-dip plating layer has a pattern part and a non-pattern part,
The pattern portion and the non-pattern portion each include one or two of a first region and a second region obtained by the following measurement method,
A hot-dip plated steel sheet, characterized in that the absolute value of the difference between the area ratio of the first region in the pattern part and the area ratio of the first region in the non-pattern part is 30% or more.
[Measuring method]
The thickness of the hot-dip plating layer is t, and a cross section of 1 to 5 mm square parallel to the surface is exposed at any position of 3t/4, t/2 or t/4 from the surface of the hot-dip plating layer. Then, virtual lattice lines were drawn at 0.5 mm intervals on each of the above-mentioned cross sections, and a ternary eutectic structure of [Zn phase] and [Al/MgZn 2 /Zn] was formed in a plurality of regions partitioned by the virtual lattice lines. The area where the ratio (B/A (%)) of the area fraction B of [Zn phase] to the total area fraction A of ] is 20% or more is defined as the first region, and the ratio (B/A (%)) The region where the difference is less than 20% is defined as the second region.
[2] Comprising a steel plate and a hot-dip plating layer formed on the surface of the steel plate,
The hot-dip plating layer has an average composition of Al: 5 to 22% by mass, Mg: 1.0 to 10% by mass, and the remainder contains Zn and impurities,
Furthermore, it contains one or two selected from the group consisting of Group A and Group B below,
The hot-dip plating layer has a pattern part and a non-pattern part,
The pattern portion and the non-pattern portion each include one or two of a first region and a second region obtained by the following measurement method,
A hot-dip plated steel sheet, characterized in that the absolute value of the difference between the area ratio of the first region in the pattern part and the area ratio of the first region in the non-pattern part is 30% or more.
[Group A] Si: 0.0001 to 2% by mass
[Group B] Any one or two of Ni, Ti, Zr, Sr, Fe, Sb, Pb, Sn, Ca, Co, Mn, P, B, Bi, Cr, Sc, Y, REM, Hf, and C 0.0001 to 2% by mass of seeds or more in total
[Measuring method]
The thickness of the hot-dip plating layer is t, and a cross section of 1 to 5 mm square parallel to the surface is exposed at any position of 3t/4, t/2 or t/4 from the surface of the hot-dip plating layer. Then, virtual lattice lines were drawn at 0.5 mm intervals on each of the above-mentioned cross sections, and a ternary eutectic structure of [Zn phase] and [Al/MgZn 2 /Zn] was formed in a plurality of regions partitioned by the virtual lattice lines. The area where the ratio (B/A (%)) of the area fraction B of [Zn phase] to the total area fraction A of ] is 20% or more is defined as the first region, and the ratio (B/A (%)) The region where the difference is less than 20% is defined as the second region.
[3] The pattern portion is arranged so as to have a shape of any one of a straight line portion, a curved portion, a dotted portion, a figure, a number, a symbol, or a character, or a combination of two or more of these. The hot-dip plated steel sheet according to [1] or [2], characterized by:
[4] The hot-dip plated steel sheet according to any one of [1] to [3], wherein the amount of the hot-dip plated layer deposited on both sides of the steel sheet is 30 to 600 g/m 2 in total.
[5] The hot-dip plated steel sheet according to any one of [2] to [4], wherein the hot-dip plated layer has an average composition containing the group A in mass %.
[6] The hot-dip plated steel sheet according to any one of [2] to [5], wherein the hot-dip plated layer has an average composition containing the group B in mass %.
［１］ 鋼板と、前記鋼板の表面に形成された溶融めっき層と、を備え、
前記溶融めっき層は、平均組成で、Ａｌ：５～２２質量％、Ｍｇ：１．０～１０質量％を含有し、残部がＺｎおよび不純物を含み、
前記溶融めっき層に、パターン部と、非パターン部とがあり、
前記パターン部及び前記非パターン部は、それぞれ、下記の測定方法で得られる第１領域、第２領域のうちの１種または２種を含み、
前記パターン部における前記第１領域の面積率と、前記非パターン部における前記第１領域の面積率との差の絶対値が、３０％以上であることを特徴とする、溶融めっき鋼板。
［測定方法］
前記溶融めっき層の厚みをｔとして、前記溶融めっき層の表面から３ｔ／４位置、ｔ／２位置またはｔ／４位置のいずれかの位置において前記表面に平行な１～５ｍｍ四方の断面を露出させ、前記の各断面に０．５ｍｍ間隔で仮想格子線を描き、前記仮想格子線によって区画される複数の領域においてそれぞれ、〔Ｚｎ相〕および〔Ａｌ／ＭｇＺｎ２／Ｚｎの三元共晶組織〕の合計面積分率Ａに対する〔Ｚｎ相〕の面積分率Ｂの比率（Ｂ／Ａ（％））が２０％以上になる領域を前記第１領域とし、比率（Ｂ／Ａ（％））が２０％未満となる領域を第２領域とする。
［２］ 鋼板と、前記鋼板の表面に形成された溶融めっき層と、を備え、
前記溶融めっき層は、平均組成で、Ａｌ：５～２２質量％、Ｍｇ：１．０～１０質量％を含有し、残部がＺｎおよび不純物を含み、
さらに下記Ａ群、Ｂ群からなる群から選択される１種または２種を含有し、
前記溶融めっき層に、パターン部と、非パターン部とがあり、
前記パターン部及び前記非パターン部は、それぞれ、下記の測定方法で得られる第１領域、第２領域のうちの１種または２種を含み、
前記パターン部における前記第１領域の面積率と、前記非パターン部における前記第１領域の面積率との差の絶対値が、３０％以上であることを特徴とする、溶融めっき鋼板。
［Ａ群］Ｓｉ：０．０００１～２質量％
［Ｂ群］Ｎｉ、Ｔｉ、Ｚｒ、Ｓｒ、Ｆｅ、Ｓｂ、Ｐｂ、Ｓｎ、Ｃａ、Ｃｏ、Ｍｎ、Ｐ、Ｂ、Ｂｉ、Ｃｒ、Ｓｃ、Ｙ、ＲＥＭ、Ｈｆ、Ｃのいずれか１種または２種以上を、合計で０．０００１～２質量％
［測定方法］
前記溶融めっき層の厚みをｔとして、前記溶融めっき層の表面から３ｔ／４位置、ｔ／２位置またはｔ／４位置のいずれかの位置において前記表面に平行な１～５ｍｍ四方の断面を露出させ、前記の各断面に０．５ｍｍ間隔で仮想格子線を描き、前記仮想格子線によって区画される複数の領域においてそれぞれ、〔Ｚｎ相〕および〔Ａｌ／ＭｇＺｎ２／Ｚｎの三元共晶組織〕の合計面積分率Ａに対する〔Ｚｎ相〕の面積分率Ｂの比率（Ｂ／Ａ（％））が２０％以上になる領域を前記第１領域とし、比率（Ｂ／Ａ（％））が２０％未満となる領域を第２領域とする。
［３］ 前記パターン部が、直線部、曲線部、ドット部、図形、数字、記号若しくは文字のいずれか１種またはこれらのうちの２種以上を組合せた形状となるように配置されていることを特徴とする［１］または［２］に記載の溶融めっき鋼板。
［４］ 前記溶融めっき層の付着量が前記鋼板両面合計で３０～６００ｇ／ｍ２であることを特徴とする［１］～［３］の何れか一項に記載の溶融めっき鋼板。
［５］ 前記溶融めっき層が、質量％で、前記Ａ群を含有する平均組成を有する［２］～［４］の何れか一項に記載の溶融めっき鋼板。
［６］ 前記溶融めっき層が、質量％で、前記Ｂ群を含有する平均組成を有する［２］～［５］の何れか一項に記載の溶融めっき鋼板。 The gist of the invention is as follows.
[1] Comprising a steel plate and a hot-dip plating layer formed on the surface of the steel plate,
The hot-dip plating layer has an average composition of Al: 5 to 22% by mass, Mg: 1.0 to 10% by mass, and the remainder contains Zn and impurities,
The hot-dip plating layer has a pattern part and a non-pattern part,
The pattern portion and the non-pattern portion each include one or two of a first region and a second region obtained by the following measurement method,
A hot-dip plated steel sheet, characterized in that the absolute value of the difference between the area ratio of the first region in the pattern part and the area ratio of the first region in the non-pattern part is 30% or more.
[Measuring method]
The thickness of the hot-dip plating layer is t, and a cross section of 1 to 5 mm square parallel to the surface is exposed at any position of 3t/4, t/2 or t/4 from the surface of the hot-dip plating layer. Then, virtual lattice lines were drawn at 0.5 mm intervals on each of the above-mentioned cross sections, and a ternary eutectic structure of [Zn phase] and [Al/MgZn 2 /Zn] was formed in a plurality of regions partitioned by the virtual lattice lines. The area where the ratio (B/A (%)) of the area fraction B of [Zn phase] to the total area fraction A of ] is 20% or more is defined as the first region, and the ratio (B/A (%)) The region where the difference is less than 20% is defined as the second region.
[2] Comprising a steel plate and a hot-dip plating layer formed on the surface of the steel plate,
The hot-dip plating layer has an average composition of Al: 5 to 22% by mass, Mg: 1.0 to 10% by mass, and the remainder contains Zn and impurities,
Furthermore, it contains one or two selected from the group consisting of Group A and Group B below,
The hot-dip plating layer has a pattern part and a non-pattern part,
The pattern portion and the non-pattern portion each include one or two of a first region and a second region obtained by the following measurement method,
A hot-dip plated steel sheet, characterized in that the absolute value of the difference between the area ratio of the first region in the pattern part and the area ratio of the first region in the non-pattern part is 30% or more.
[Group A] Si: 0.0001 to 2% by mass
[Group B] Any one or two of Ni, Ti, Zr, Sr, Fe, Sb, Pb, Sn, Ca, Co, Mn, P, B, Bi, Cr, Sc, Y, REM, Hf, and C 0.0001 to 2% by mass of seeds or more in total
[Measuring method]
The thickness of the hot-dip plating layer is t, and a cross section of 1 to 5 mm square parallel to the surface is exposed at any position of 3t/4, t/2 or t/4 from the surface of the hot-dip plating layer. Then, virtual lattice lines were drawn at 0.5 mm intervals on each of the above-mentioned cross sections, and a ternary eutectic structure of [Zn phase] and [Al/MgZn 2 /Zn] was formed in a plurality of regions partitioned by the virtual lattice lines. The area where the ratio (B/A (%)) of the area fraction B of [Zn phase] to the total area fraction A of ] is 20% or more is defined as the first region, and the ratio (B/A (%)) The region where the difference is less than 20% is defined as the second region.
[3] The pattern portion is arranged so as to have a shape of any one of a straight line portion, a curved portion, a dotted portion, a figure, a number, a symbol, or a character, or a combination of two or more of these. The hot-dip plated steel sheet according to [1] or [2], characterized by:
[4] The hot-dip plated steel sheet according to any one of [1] to [3], wherein the amount of the hot-dip plated layer deposited on both sides of the steel sheet is 30 to 600 g/m 2 in total.
[5] The hot-dip plated steel sheet according to any one of [2] to [4], wherein the hot-dip plated layer has an average composition containing the group A in mass %.
[6] The hot-dip plated steel sheet according to any one of [2] to [5], wherein the hot-dip plated layer has an average composition containing the group B in mass %.
本発明によれば、溶融めっき層の表面に文字やデザイン等を現すことができ、それらの耐久性に優れ、また、耐食性にも優れた溶融めっき鋼板を提供できる。
According to the present invention, it is possible to provide a hot-dip plated steel sheet that can display characters, designs, etc. on the surface of the hot-dip plated layer, has excellent durability, and is also excellent in corrosion resistance.
本発明者らは、梨地状の外観を呈するＺｎ－Ａｌ－Ｍｇ系溶融めっき鋼板のめっき層を詳細に調査した。梨地状の外観は、金属光沢を示す微細な金属光沢部分と、白色を呈する微細な白色部分とが混在することによって現れる。このうち、金属光沢部分におけるめっき層の組織を調べたところ、めっき層表面における〔Ｚｎ相〕の面積分率が、白色部分に比べて少なくなっていることを見出した。他方、白色部分におけるめっき層の組織を調べたところ、〔Ａｌ／ＭｇＺｎ２／Ｚｎの三元共晶組織〕に対する〔Ｚｎ相〕の割合が金属光沢部分に比べて高くなっていることを見出した。
The present inventors investigated in detail the plating layer of a Zn-Al-Mg hot-dip plated steel sheet exhibiting a satin-like appearance. The satin-like appearance is caused by the coexistence of fine metallic luster parts exhibiting metallic luster and fine white parts exhibiting white color. When the structure of the plating layer in the metallic luster portion was examined, it was found that the area fraction of the [Zn phase] on the surface of the plating layer was smaller than that in the white portion. On the other hand, when the structure of the plating layer in the white part was investigated, it was found that the ratio of the [Zn phase] to the [ternary eutectic structure of Al/MgZn 2 /Zn] was higher than that in the metallic luster part. .
そこで、溶融めっき層において、金属光沢部分と白色部分の分布状態を任意に制御できるかどうか検討したところ、溶融めっき層の化学成分を調整するとともに、鋼板を溶融めっき浴に浸漬させる前に、鋼板表面に、清浄度が比較的低い領域を意図的な形状になるように配置した上で溶融めっきを行うことにより、溶融めっき層表面において金属光沢部分が比較的多く含まれる領域を、意図的に配置できることを見出し、本発明を完成させた。
Therefore, we investigated whether it was possible to arbitrarily control the distribution of the metallic luster and white parts in the hot-dip coating layer.We decided to adjust the chemical composition of the hot-dip coating layer and to By arranging areas with relatively low cleanliness on the surface in an intentional shape and then performing hot-dip plating, areas containing relatively many metallic luster areas on the surface of the hot-dip plating layer are intentionally created. The present invention was completed based on the discovery that it is possible to
以下、本発明の実施形態である溶融めっき鋼板について説明する。
本実施形態の溶融めっき鋼板は、図１～図３に示されるように、鋼板１と、鋼板１の表面に形成された溶融めっき層と２、を備え、溶融めっき層２は、平均組成で、Ａｌ：５～２２質量％、Ｍｇ：１～１０質量％を含有し、残部がＺｎおよび不純物を含み、溶融めっき層２に、パターン部２１と、非パターン部２２とがあり、パターン部２１及び非パターン部２２は、それぞれ、下記の測定方法で得られる第１領域Ａ１、第２領域Ａ２のうちの１種または２種を含み、パターン部２１における第１領域Ａ１の面積率と、非パターン部２２における第１領域Ａ１の面積率との差の絶対値が、３０％以上である溶融めっき鋼板である。 Hereinafter, a hot-dipped steel plate that is an embodiment of the present invention will be described.
As shown in FIGS. 1 to 3, the hot-dip plated steel sheet of this embodiment includes asteel plate 1 and a hot-dip plated layer 2 formed on the surface of the steel plate 1, and the hot-dip plated layer 2 has an average composition. , Al: 5 to 22% by mass, Mg: 1 to 10% by mass, and the remainder contains Zn and impurities. and the non-patterned area 22 each include one or two of the first area A1 and the second area A2 obtained by the following measurement method, and the area ratio of the first area A1 in the patterned area 21 and the non-patterned area are This is a hot-dip plated steel sheet in which the absolute value of the difference from the area ratio of the first region A1 in the pattern portion 22 is 30% or more.
本実施形態の溶融めっき鋼板は、図１～図３に示されるように、鋼板１と、鋼板１の表面に形成された溶融めっき層と２、を備え、溶融めっき層２は、平均組成で、Ａｌ：５～２２質量％、Ｍｇ：１～１０質量％を含有し、残部がＺｎおよび不純物を含み、溶融めっき層２に、パターン部２１と、非パターン部２２とがあり、パターン部２１及び非パターン部２２は、それぞれ、下記の測定方法で得られる第１領域Ａ１、第２領域Ａ２のうちの１種または２種を含み、パターン部２１における第１領域Ａ１の面積率と、非パターン部２２における第１領域Ａ１の面積率との差の絶対値が、３０％以上である溶融めっき鋼板である。 Hereinafter, a hot-dipped steel plate that is an embodiment of the present invention will be described.
As shown in FIGS. 1 to 3, the hot-dip plated steel sheet of this embodiment includes a
パターン部２１における第１領域Ａ１の面積率、及び非パターン部２２における第１領域Ａ１の面積率の測定方法は、次の通りである。溶融めっき層２の厚みをｔとして、溶融めっき層２の表面から３ｔ／４位置、ｔ／２位置またはｔ／４位置のいずれかの位置において、溶融めっき層２の表面２ａに平行な１～５ｍｍ四方の断面を露出させる。そして、図３に例示されるように、各断面に０．５ｍｍ間隔で仮想格子線を描き、仮想格子線によって区画される複数の領域においてそれぞれ、〔Ｚｎ相〕および〔Ａｌ／ＭｇＺｎ２／Ｚｎの三元共晶組織〕の合計面積分率Ａに対する〔Ｚｎ相〕の面積分率Ｂの比率（Ｂ／Ａ（％））が２０％以上になる領域を第１領域Ａ１とし、比率（Ｂ／Ａ（％））が２０％未満となる領域を第２領域Ａ２とする。
なお、図３に例示される測定用の露出面は、５ｍｍ四方の正方形である。当該露出面において、仮想格子線によって区画される領域の数は１００である。パターン部が小さく、５ｍｍ四方の露出面をパターン部の内部に形成できない場合は、露出面のサイズを小さくしてもよい。この場合、複数の露出面を形成し、これにより、仮想格子線によって区画される領域の数の合計値を１００とする。例えば露出面を１ｍｍ四方の正方形とした場合、１つの当該露出面において、仮想格子線によって区画される領域の数は４である。１ｍｍ四方の露出面を２５箇所で形成すると、仮想格子線によって区画される領域の数の合計値が１００となる。
なお、パターン部の個数は２以上であってもよい。この場合において、測定用の露出面は、複数のパターン部それぞれに形成してもよい。
パターン部が非常に狭く、仮想格子線によって区画される領域の数を１００とすることができない場合は、仮想格子線の間隔を狭めてもよい。例えば、仮想格子線の間隔を０．２ｍｍ以上０．５ｍｍ未満の値に変更してもよい。仮想格子線の間隔を狭めることにより、非常に狭いパターン部の内部において、仮想格子線によって区画される領域（即ち測定点）の数を１００とすることができる。
パターン部の内部に複数の露出面を形成する場合、これら露出面同士の距離は可能な限り小さくする。パターン部の内部に形成される複数の露出面が接していてもよい。非パターン部の内部に複数の露出面が形成される場合も、複数の露出面同士の距離は可能な限り小さくすることが好ましく、複数の露出面が接していてもよい。
また、パターン部２１における第１領域Ａ１の面積率、及び非パターン部２２における第１領域Ａ１の面積率を測定する際には、パターン部の内部に形成される露出面と、非パターン部の内部に形成される露出面との間の距離も、可能な限り小さくすることが好ましい。 The method of measuring the area ratio of the first region A1 in thepattern portion 21 and the area ratio of the first region A1 in the non-pattern portion 22 is as follows. 1 to 1 parallel to the surface 2a of the hot-dip plating layer 2 at any position 3t/4, t/2 or t/4 from the surface of the hot-dip plating layer 2, where the thickness of the hot-dip plating layer 2 is t. Expose a 5mm square cross section. Then, as illustrated in FIG. 3, virtual grid lines are drawn at 0.5 mm intervals on each cross section, and [Zn phase] and [Al/MgZn 2 /Zn A region where the ratio (B/A (%)) of the area fraction B of the [Zn phase] to the total area fraction A of the ternary eutectic structure] is 20% or more is defined as the first region A1, and the ratio (B The area where /A (%)) is less than 20% is defined as a second area A2.
Note that the exposed surface for measurement illustrated in FIG. 3 is a 5 mm square. On the exposed surface, the number of regions defined by virtual grid lines is 100. If the pattern section is small and an exposed surface of 5 mm square cannot be formed inside the pattern section, the size of the exposed surface may be reduced. In this case, a plurality of exposed surfaces are formed, so that the total number of regions defined by the virtual grid lines is 100. For example, when the exposed surface is a 1 mm square, the number of regions defined by virtual grid lines in one exposed surface is four. If a 1 mm square exposed surface is formed at 25 locations, the total number of regions defined by the virtual grid lines will be 100.
Note that the number of pattern parts may be two or more. In this case, the exposed surface for measurement may be formed in each of the plurality of pattern parts.
If the pattern section is very narrow and the number of regions partitioned by the virtual grid lines cannot be set to 100, the intervals between the virtual grid lines may be narrowed. For example, the interval between the virtual grid lines may be changed to a value of 0.2 mm or more and less than 0.5 mm. By narrowing the interval between the virtual grid lines, the number of regions (i.e., measurement points) defined by the virtual grid lines can be set to 100 within a very narrow pattern section.
When forming a plurality of exposed surfaces inside the pattern section, the distance between these exposed surfaces is made as small as possible. A plurality of exposed surfaces formed inside the pattern portion may be in contact with each other. Even when a plurality of exposed surfaces are formed inside the non-patterned portion, it is preferable that the distance between the plurality of exposed surfaces be as small as possible, and the plurality of exposed surfaces may be in contact with each other.
Furthermore, when measuring the area ratio of the first area A1 in thepattern part 21 and the area ratio of the first area A1 in the non-pattern part 22, the exposed surface formed inside the pattern part and the area ratio of the non-pattern part are measured. It is also preferable that the distance between the exposed surface and the exposed surface formed inside is as small as possible.
なお、図３に例示される測定用の露出面は、５ｍｍ四方の正方形である。当該露出面において、仮想格子線によって区画される領域の数は１００である。パターン部が小さく、５ｍｍ四方の露出面をパターン部の内部に形成できない場合は、露出面のサイズを小さくしてもよい。この場合、複数の露出面を形成し、これにより、仮想格子線によって区画される領域の数の合計値を１００とする。例えば露出面を１ｍｍ四方の正方形とした場合、１つの当該露出面において、仮想格子線によって区画される領域の数は４である。１ｍｍ四方の露出面を２５箇所で形成すると、仮想格子線によって区画される領域の数の合計値が１００となる。
なお、パターン部の個数は２以上であってもよい。この場合において、測定用の露出面は、複数のパターン部それぞれに形成してもよい。
パターン部が非常に狭く、仮想格子線によって区画される領域の数を１００とすることができない場合は、仮想格子線の間隔を狭めてもよい。例えば、仮想格子線の間隔を０．２ｍｍ以上０．５ｍｍ未満の値に変更してもよい。仮想格子線の間隔を狭めることにより、非常に狭いパターン部の内部において、仮想格子線によって区画される領域（即ち測定点）の数を１００とすることができる。
パターン部の内部に複数の露出面を形成する場合、これら露出面同士の距離は可能な限り小さくする。パターン部の内部に形成される複数の露出面が接していてもよい。非パターン部の内部に複数の露出面が形成される場合も、複数の露出面同士の距離は可能な限り小さくすることが好ましく、複数の露出面が接していてもよい。
また、パターン部２１における第１領域Ａ１の面積率、及び非パターン部２２における第１領域Ａ１の面積率を測定する際には、パターン部の内部に形成される露出面と、非パターン部の内部に形成される露出面との間の距離も、可能な限り小さくすることが好ましい。 The method of measuring the area ratio of the first region A1 in the
Note that the exposed surface for measurement illustrated in FIG. 3 is a 5 mm square. On the exposed surface, the number of regions defined by virtual grid lines is 100. If the pattern section is small and an exposed surface of 5 mm square cannot be formed inside the pattern section, the size of the exposed surface may be reduced. In this case, a plurality of exposed surfaces are formed, so that the total number of regions defined by the virtual grid lines is 100. For example, when the exposed surface is a 1 mm square, the number of regions defined by virtual grid lines in one exposed surface is four. If a 1 mm square exposed surface is formed at 25 locations, the total number of regions defined by the virtual grid lines will be 100.
Note that the number of pattern parts may be two or more. In this case, the exposed surface for measurement may be formed in each of the plurality of pattern parts.
If the pattern section is very narrow and the number of regions partitioned by the virtual grid lines cannot be set to 100, the intervals between the virtual grid lines may be narrowed. For example, the interval between the virtual grid lines may be changed to a value of 0.2 mm or more and less than 0.5 mm. By narrowing the interval between the virtual grid lines, the number of regions (i.e., measurement points) defined by the virtual grid lines can be set to 100 within a very narrow pattern section.
When forming a plurality of exposed surfaces inside the pattern section, the distance between these exposed surfaces is made as small as possible. A plurality of exposed surfaces formed inside the pattern portion may be in contact with each other. Even when a plurality of exposed surfaces are formed inside the non-patterned portion, it is preferable that the distance between the plurality of exposed surfaces be as small as possible, and the plurality of exposed surfaces may be in contact with each other.
Furthermore, when measuring the area ratio of the first area A1 in the
本実施形態の溶融めっき鋼板では、溶融めっき層２の表面から３ｔ／４位置、ｔ／２位置またはｔ／４位置のいずれかの位置において１～５ｍｍ四方の断面を露出させ、当該断面に０．５ｍｍ間隔で仮想格子線を描いた場合に、仮想格子線によって区画される複数の領域が、第１領域Ａ１または第２領域Ａ２のいずれかに区分される。第１領域Ａ１、第２領域Ａ２のいずれに区分されるかは、〔Ｚｎ相〕および〔Ａｌ／ＭｇＺｎ２／Ｚｎの三元共晶組織〕の合計面積分率Ａに対する〔Ｚｎ相〕の面積分率Ｂの比率（Ｂ／Ａ（％））に応じて決定する。
In the hot-dip plated steel sheet of this embodiment, a cross section of 1 to 5 mm square is exposed at any position of 3t/4 position, t/2 position, or t/4 position from the surface of hot-dip coating layer 2, and the cross section is When virtual grid lines are drawn at intervals of .5 mm, a plurality of regions defined by the virtual grid lines are divided into either a first region A1 or a second region A2. The area of the [Zn phase] relative to the total area fraction A of the [Zn phase] and [ternary eutectic structure of Al/MgZn 2 /Zn] determines whether it is divided into the first region A1 or the second region A2. It is determined according to the ratio of fraction B (B/A (%)).
第１領域Ａ１は、比率（Ｂ／Ａ（％））が２０％以上になる領域とする。第１領域Ａ１は比率（Ｂ／Ａ（％））が高いため、溶融めっき層２において第１領域が多く含まれる箇所は、肉眼または顕微鏡下で観察した際に、白色もしくは白色に近い色に見える。一方、第２領域Ａ２は、比率（Ｂ／Ａ（％））が２０％未満の領域とする。第２領域Ａ２は、比率（Ｂ／Ａ（％））が低いため、溶融めっき層において第２領域Ａ２が多く含まれて第１領域Ａ１が少なくなる箇所は、肉眼または顕微鏡下で観察した際に、金属光沢があるように見える。更に、第１領域Ａ１と第２領域Ａ２とが混在し、第１領域Ａ１の面積率が３０～７０％である箇所は、外観が梨地状に見える。
The first area A1 is an area where the ratio (B/A (%)) is 20% or more. Since the ratio (B/A (%)) of the first area A1 is high, the areas in the hot-dip plating layer 2 that contain a large amount of the first area appear white or close to white when observed with the naked eye or under a microscope. appear. On the other hand, the second area A2 is an area where the ratio (B/A (%)) is less than 20%. The second area A2 has a low ratio (B/A (%)), so when observed with the naked eye or under a microscope, the hot-dip plating layer contains a large amount of the second area A2 and a small amount of the first area A1. It appears to have a metallic luster. Further, in areas where the first area A1 and the second area A2 coexist and the area ratio of the first area A1 is 30 to 70%, the appearance appears satin-like.
このように、第１領域Ａ１の面積率によって、溶融めっき層２の表面２ａは、白色もしくは白色に近い色、金属光沢または梨地状に見える。ここで、溶融めっき層２の表面２ａに、文字、図形、線、ドットなどが視認できるようにするためには、これらの文字等を構成するパターン部２１と、それ以外の非パターン部２２とが、識別できるようになればよい。そのためには、パターン部２１における第１領域Ａ１の面積割合と、非パターン部２２における第１領域Ａ１の面積割合とが、異なっていればよい。
As described above, depending on the area ratio of the first region A1, the surface 2a of the hot-dip plating layer 2 appears white or nearly white, has a metallic luster, or has a satin finish. Here, in order to make characters, figures, lines, dots, etc. visible on the surface 2a of the hot-dip plating layer 2, it is necessary to separate the pattern part 21 that constitutes these characters, etc. and the other non-pattern part 22. It would be good if it could be identified. For this purpose, the area ratio of the first region A1 in the pattern portion 21 and the area ratio of the first region A1 in the non-pattern portion 22 need only be different.
具体的には、パターン部２１における第１領域Ａ１の面積率と、非パターン部２２における第１領域Ａ１の面積率との差が、絶対値で３０％以上であるとよい。これにより、パターン部２１と非パターン部２２とが識別可能になる。なお、面積率の差を評価する際には、パターン部２１及び非パターン部２２の全域を評価する必要はない。図３に示されるように、パターン部２１の内部に設けられる測定用の１～５ｍｍ四方の面（露出面）における第１領域Ａ１の面積率を、パターン部２１全体における第１領域Ａ１の面積率とみなすことができる。同様に、非パターン部２２の内部に設けられる測定用の１～５ｍｍ四方の面（露出面）における第１領域Ａ１の面積率を、非パターン部２２全体における第１領域Ａ１の面積率とみなすことができる。
パターン部２１の視認性を一層向上させる観点から、パターン部２１における第１領域Ａ１の面積率と、非パターン部２２における第１領域Ａ１の面積率との差の絶対値が４０％以上、４５％以上、又は５０％以上であってもよい。パターン部２１における第１領域Ａ１の面積率と、非パターン部２２における第１領域Ａ１の面積率との差の絶対値の上限を設ける必要はないが、例えばパターン部２１における第１領域Ａ１の面積率と、非パターン部２２における第１領域Ａ１の面積率との差の絶対値を９５％以下、９０％以下、又は８５％以下としてもよい。 Specifically, the difference between the area ratio of the first region A1 in thepattern portion 21 and the area ratio of the first region A1 in the non-pattern portion 22 is preferably 30% or more in absolute value. Thereby, the pattern portion 21 and the non-pattern portion 22 can be distinguished. Note that when evaluating the difference in area ratio, it is not necessary to evaluate the entire area of the pattern portion 21 and the non-pattern portion 22. As shown in FIG. 3, the area ratio of the first region A1 in the 1 to 5 mm square surface (exposed surface) for measurement provided inside the pattern section 21 is calculated as the area ratio of the first region A1 in the entire pattern section 21. It can be considered as a rate. Similarly, the area ratio of the first area A1 on the 1-5 mm square surface (exposed surface) for measurement provided inside the non-pattern part 22 is regarded as the area ratio of the first area A1 in the entire non-pattern part 22. be able to.
From the viewpoint of further improving the visibility of thepattern section 21, the absolute value of the difference between the area ratio of the first region A1 in the pattern section 21 and the area ratio of the first region A1 in the non-pattern section 22 is 40% or more, 45 % or more, or 50% or more. Although it is not necessary to set an upper limit on the absolute value of the difference between the area ratio of the first area A1 in the pattern part 21 and the area ratio of the first area A1 in the non-pattern part 22, for example, The absolute value of the difference between the area ratio and the area ratio of the first region A1 in the non-pattern portion 22 may be 95% or less, 90% or less, or 85% or less.
パターン部２１の視認性を一層向上させる観点から、パターン部２１における第１領域Ａ１の面積率と、非パターン部２２における第１領域Ａ１の面積率との差の絶対値が４０％以上、４５％以上、又は５０％以上であってもよい。パターン部２１における第１領域Ａ１の面積率と、非パターン部２２における第１領域Ａ１の面積率との差の絶対値の上限を設ける必要はないが、例えばパターン部２１における第１領域Ａ１の面積率と、非パターン部２２における第１領域Ａ１の面積率との差の絶対値を９５％以下、９０％以下、又は８５％以下としてもよい。 Specifically, the difference between the area ratio of the first region A1 in the
From the viewpoint of further improving the visibility of the
例えば、パターン部２１における第１領域Ａ１の面積割合が７５％である場合、パターン部２１は白色若しくは白色に近い色に見える。また、非パターン部２２における第１領域Ａ１の面積割合が４５％以下である場合、梨地状、あるいは金属光沢があるように見える。そして、パターン部２１、非パターン部２２における第１領域Ａ１の面積率の差が３０％以上の場合に、このような外観の違いにより、パターン部２１と非パターン部２２が識別可能になる。
For example, when the area ratio of the first region A1 in the pattern portion 21 is 75%, the pattern portion 21 appears white or a color close to white. Furthermore, when the area ratio of the first region A1 in the non-patterned portion 22 is 45% or less, it appears satin-like or has metallic luster. When the difference in area ratio of the first area A1 between the pattern section 21 and the non-pattern section 22 is 30% or more, the pattern section 21 and the non-pattern section 22 can be distinguished from each other due to such a difference in appearance.
また、パターン部２１の第１領域Ａ１の面積割合が６５％程度であり、非パターン部２２の第１領域Ａ１の面積割合が３５％程度である場合、パターン部２１及び非パターン部２２はともに梨地状に見えるが、パターン部２１における第１領域Ａ１の面積割合が大きいため、パターン部２１は非パターン部２２に対してより白い外観を呈する。そして、パターン部２１、非パターン部２２における第１領域Ａ１の面積率の差が３０％以上の場合に、このような外観の違いにより、パターン部２１と非パターン部２２が識別可能になる。
Further, when the area ratio of the first region A1 of the pattern section 21 is about 65% and the area ratio of the first region A1 of the non-pattern section 22 is about 35%, both the pattern section 21 and the non-pattern section 22 are Although it looks satin-like, since the area ratio of the first region A1 in the pattern section 21 is large, the pattern section 21 has a whiter appearance than the non-pattern section 22. When the difference in area ratio of the first area A1 between the pattern section 21 and the non-pattern section 22 is 30% or more, the pattern section 21 and the non-pattern section 22 can be distinguished from each other due to such a difference in appearance.
更に、パターン部２１の第１領域Ａ１が５０％である場合、パターン部２１は梨地状に見える。また、非パターン部２２における第１領域Ａ１の面積割合が２０％以下である場合、金属光沢があるように見える。そして、パターン部２１、非パターン部２２における第１領域Ａ１の面積率の差が３０％以上の場合に、このような外観の違いにより、パターン部２１と非パターン部２２が識別可能になる。
Further, when the first area A1 of the pattern portion 21 is 50%, the pattern portion 21 appears satin-like. Further, when the area ratio of the first region A1 in the non-patterned portion 22 is 20% or less, it appears to have metallic luster. When the difference in area ratio of the first area A1 between the pattern section 21 and the non-pattern section 22 is 30% or more, the pattern section 21 and the non-pattern section 22 can be distinguished from each other due to such a difference in appearance.
このように、パターン部２１における第１領域Ａ１の面積率と非パターン部２２における第１領域Ａ１の面積率との差が絶対値で３０％以上になると、パターン部２１と非パターン部２２の外観が異なるようになるため、パターン部２１を明確に識別できるようになる。すなわち、めっき層２の表面２ａの可視光像において、パターン部２１及び非パターン部２２の色相、明度、彩度等の差が大きくなるため、パターン部２１と非パターン部２２が識別可能になる。
In this way, when the difference between the area ratio of the first area A1 in the pattern part 21 and the area ratio of the first area A1 in the non-pattern part 22 becomes 30% or more in absolute value, the pattern part 21 and the non-pattern part 22 Since the appearance is different, the pattern portion 21 can be clearly identified. That is, in the visible light image of the surface 2a of the plating layer 2, the difference in hue, brightness, chroma, etc. between the pattern portion 21 and the non-pattern portion 22 becomes large, so that the pattern portion 21 and the non-pattern portion 22 become distinguishable. .
一方、パターン部２１における第１領域Ａ１の面積率と非パターン部２２における第１領域Ａ１の面積率との差が絶対値で３０％未満になると、パターン部２１と非パターン部２２の外観の差がなくなり、パターン部２１を明確に識別できなくなる。すなわち、めっき層２の表面２ａの可視光像において、パターン部２１及び非パターン部２２の色相、明度、彩度等の差が小さくなるため、パターン部２１と非パターン部２２が識別できなくなる。
On the other hand, if the difference between the area ratio of the first area A1 in the pattern part 21 and the area ratio of the first area A1 in the non-pattern part 22 becomes less than 30% in absolute value, the appearance of the pattern part 21 and the non-pattern part 22 will change. There is no difference, and the pattern portion 21 cannot be clearly identified. That is, in the visible light image of the surface 2a of the plating layer 2, the difference in hue, brightness, chroma, etc. between the pattern portion 21 and the non-pattern portion 22 becomes small, so that the pattern portion 21 and the non-pattern portion 22 cannot be distinguished.
以上のように、パターン部２１及び非パターン部２２における第１領域Ａ１の存在割合の一例を示したが、パターン部２１における第１領域Ａ１の面積率と非パターン部２２における第１領域Ａ１の面積率との差が絶対値で３０％以上であればよく、パターン部２１及び非パターン部２２のそれぞれにおける第１領域Ａ１の存在割合を限定する必要はない。
As described above, an example of the existence ratio of the first area A1 in the pattern part 21 and the non-pattern part 22 has been shown. It is sufficient that the difference from the area ratio is 30% or more in absolute value, and there is no need to limit the proportion of the first area A1 in each of the pattern portion 21 and the non-pattern portion 22.
溶融めっき層の下地となる鋼板は、材質に特に制限はない。詳細は後述するが、材質として、一般鋼などを特に制限はなく用いることができ、Ａｌキルド鋼や一部の高合金鋼も適用することも可能であり、形状にも特に制限はない。鋼板に対して後述する溶融めっき法を適用することで、本実施形態に係る溶融めっき層が形成される。
There are no particular restrictions on the material of the steel plate that serves as the base for the hot-dip plating layer. Although details will be described later, general steel or the like can be used as the material without any particular restriction, and Al-killed steel or some high-alloy steel can also be used, and there is no particular restriction on the shape. The hot-dip plating layer according to this embodiment is formed by applying the hot-dip plating method described below to the steel plate.
次に、溶融めっき層の化学成分について説明する。
溶融めっき層は、平均組成で、Ａｌ：５～２２質量％、Ｍｇ：１．０～１０質量％を含有し、残部としてＺｎおよび不純物を含む。好ましくは、平均組成で、Ａｌ：５～２２質量％、Ｍｇ：１．０～１０質量％を含有し、残部としてＺｎおよび不純物からなる。
また、溶融めっき層は、下記Ａ群、Ｂ群からなる群から選択される１種または２種を含有してもよい。
［Ａ群］Ｓｉ：０．０００１～２質量％
［Ｂ群］Ｎｉ、Ｔｉ、Ｚｒ、Ｓｒ、Ｆｅ、Ｓｂ、Ｐｂ、Ｓｎ、Ｃａ、Ｃｏ、Ｍｎ、Ｐ、Ｂ、Ｂｉ、Ｃｒ、Ｓｃ、Ｙ、ＲＥＭ、Ｈｆ、Ｃのいずれか１種または２種以上を、合計で０．０００１～２質量％ Next, the chemical components of the hot-dip plating layer will be explained.
The average composition of the hot-dip plating layer is Al: 5 to 22% by mass, Mg: 1.0 to 10% by mass, and the balance includes Zn and impurities. Preferably, the average composition contains Al: 5 to 22% by mass, Mg: 1.0 to 10% by mass, and the remainder consists of Zn and impurities.
Further, the hot-dip plating layer may contain one or two selected from the group consisting of Group A and Group B below.
[Group A] Si: 0.0001 to 2% by mass
[Group B] Any one or two of Ni, Ti, Zr, Sr, Fe, Sb, Pb, Sn, Ca, Co, Mn, P, B, Bi, Cr, Sc, Y, REM, Hf, and C 0.0001 to 2% by mass of seeds or more in total
溶融めっき層は、平均組成で、Ａｌ：５～２２質量％、Ｍｇ：１．０～１０質量％を含有し、残部としてＺｎおよび不純物を含む。好ましくは、平均組成で、Ａｌ：５～２２質量％、Ｍｇ：１．０～１０質量％を含有し、残部としてＺｎおよび不純物からなる。
また、溶融めっき層は、下記Ａ群、Ｂ群からなる群から選択される１種または２種を含有してもよい。
［Ａ群］Ｓｉ：０．０００１～２質量％
［Ｂ群］Ｎｉ、Ｔｉ、Ｚｒ、Ｓｒ、Ｆｅ、Ｓｂ、Ｐｂ、Ｓｎ、Ｃａ、Ｃｏ、Ｍｎ、Ｐ、Ｂ、Ｂｉ、Ｃｒ、Ｓｃ、Ｙ、ＲＥＭ、Ｈｆ、Ｃのいずれか１種または２種以上を、合計で０．０００１～２質量％ Next, the chemical components of the hot-dip plating layer will be explained.
The average composition of the hot-dip plating layer is Al: 5 to 22% by mass, Mg: 1.0 to 10% by mass, and the balance includes Zn and impurities. Preferably, the average composition contains Al: 5 to 22% by mass, Mg: 1.0 to 10% by mass, and the remainder consists of Zn and impurities.
Further, the hot-dip plating layer may contain one or two selected from the group consisting of Group A and Group B below.
[Group A] Si: 0.0001 to 2% by mass
[Group B] Any one or two of Ni, Ti, Zr, Sr, Fe, Sb, Pb, Sn, Ca, Co, Mn, P, B, Bi, Cr, Sc, Y, REM, Hf, and C 0.0001 to 2% by mass of seeds or more in total
Ａｌの含有量は、平均組成で５～２２質量％の範囲である。Ａｌは、耐食性を確保するために含有させるとよい。溶融めっき層中のＡｌの含有量が５質量％以上であれば、耐食性を向上させる効果がより高まる。２２質量％以下であれば、めっき層を安定して形成できる。２２質量％を超えると耐食性を向上させる効果が飽和する。Ａｌの含有量は、耐食性の観点から、より好ましくは６質量％以上、８質量％以上又は１１質量％以上である。Ａｌの含有量は、耐食性の観点から、より好ましくは２０質量％以下、１９質量％以下、又は１７質量％以下である。
The content of Al is in the range of 5 to 22% by mass in terms of average composition. Al is preferably included in order to ensure corrosion resistance. If the content of Al in the hot-dip plating layer is 5% by mass or more, the effect of improving corrosion resistance will be further enhanced. If it is 22% by mass or less, a plating layer can be stably formed. When it exceeds 22% by mass, the effect of improving corrosion resistance is saturated. From the viewpoint of corrosion resistance, the Al content is more preferably 6% by mass or more, 8% by mass or more, or 11% by mass or more. From the viewpoint of corrosion resistance, the Al content is more preferably 20% by mass or less, 19% by mass or less, or 17% by mass or less.
Ｍｇの含有量は、平均組成で１．０～１０質量％の範囲である。Ｍｇは、耐食性を向上させるために含有させるとよい。溶融めっき層中のＭｇの含有量が１．０質量％以上であれば、耐食性を向上させる効果がより高まる。１０質量％を超えるとめっき浴でのドロス発生が著しくなり、安定的に溶融めっき鋼板を製造するのが困難となる。Ｍｇの含有量は、耐食性とドロス発生のバランスの観点から、好ましくは１．５質量％以上、２質量％以上、又は４質量％以上とする。Ｍｇの含有量は、耐食性とドロス発生のバランスの観点から、好ましくは８質量％以下、７質量%以下、又は６質量％以下とする。
The Mg content is in the range of 1.0 to 10% by mass in terms of average composition. Mg is preferably included in order to improve corrosion resistance. If the content of Mg in the hot-dip plating layer is 1.0% by mass or more, the effect of improving corrosion resistance will be further enhanced. If it exceeds 10% by mass, dross generation in the plating bath becomes significant, making it difficult to stably produce hot-dip plated steel sheets. From the viewpoint of the balance between corrosion resistance and dross generation, the content of Mg is preferably 1.5% by mass or more, 2% by mass or more, or 4% by mass or more. From the viewpoint of the balance between corrosion resistance and dross generation, the Mg content is preferably 8% by mass or less, 7% by mass or less, or 6% by mass or less.
また、溶融めっき層は、Ｓｉを０．０００１～２質量％の範囲で含有していてもよい。Ｓｉは、溶融めっき層の密着性を向上させる場合があるので、含有させてもよい。Ｓｉを０．０００１質量％以上含有させることで密着性を向上させる効果が発現するため、Ｓｉを０．０００１質量％以上含有させることが好ましい。一方、２質量％を超えて含有させてもめっき密着性を向上させる効果が飽和するため、Ｓｉの含有量は２質量％以下とする。Ｓｉの含有量は、めっき密着性の観点からは、好ましくは０．０１００質量％以上、０．０３００質量％以上、又は０．１０００質量％以上である。Ｓｉの含有量は、１質量％以下、０．９質量％以下、又は０．８質量％としてもよい。
Furthermore, the hot-dip plating layer may contain Si in a range of 0.0001 to 2% by mass. Si may improve the adhesion of the hot-dip plating layer, so it may be included. It is preferable to contain Si in an amount of 0.0001% by mass or more because the effect of improving adhesion is exhibited by containing 0.0001% by mass or more of Si. On the other hand, the effect of improving plating adhesion is saturated even if the content exceeds 2% by mass, so the content of Si is set to 2% by mass or less. From the viewpoint of plating adhesion, the Si content is preferably 0.0100% by mass or more, 0.0300% by mass or more, or 0.1000% by mass or more. The content of Si may be 1% by mass or less, 0.9% by mass or less, or 0.8% by mass.
溶融めっき層中には、平均組成で、Ｎｉ、Ｔｉ、Ｚｒ、Ｓｒ、Ｆｅ、Ｓｂ、Ｐｂ、Ｓｎ、Ｃａ、Ｃｏ、Ｍｎ、Ｐ、Ｂ、Ｂｉ、Ｃｒ、Ｓｃ、Ｙ、ＲＥＭ、Ｈｆ、Ｃの１種又は２種以上を合計で０．０００１～２質量％を含有していてもよい。これらの元素を含有することで、さらに耐食性を改善することができる。ＲＥＭは、周期律表における原子番号５７～７１の希土類元素の１種または２種以上である。
The average composition of the hot-dip plating layer is Ni, Ti, Zr, Sr, Fe, Sb, Pb, Sn, Ca, Co, Mn, P, B, Bi, Cr, Sc, Y, REM, Hf, C. It may contain one or more of the following in a total amount of 0.0001 to 2% by mass. By containing these elements, corrosion resistance can be further improved. REM is one or more rare earth elements with atomic numbers 57 to 71 in the periodic table.
溶融めっき層の化学成分の残部は、亜鉛及び不純物である。不純物には、亜鉛ほかの地金中に不可避的に含まれるもの、めっき浴中で、鋼が溶解することによって含まれるものがある。
The remainder of the chemical components of the hot-dip plated layer are zinc and impurities. Impurities include those that are unavoidably included in base metals such as zinc, and those that are included when steel is melted in a plating bath.
なお、溶融めっき層の平均組成は、次のような方法で測定できる。まず、めっきを浸食しない塗膜剥離剤（例えば、三彩化工社製ネオリバーＳＰ－７５１）で表層塗膜を除去した後に、インヒビター（例えば、スギムラ化学工業社製ヒビロン）入りの塩酸で溶融めっき層を溶解し、得られた溶液を誘導結合プラズマ（ＩＣＰ）発光分光分析に供することで求めることができる。また、表層塗膜を有しない場合は、表層塗膜の除去作業を省略できる。
Note that the average composition of the hot-dip plating layer can be measured by the following method. First, the surface coating film is removed with a paint film remover that does not corrode the plating (for example, Neoliver SP-751 manufactured by Sansai Kako Co., Ltd.), and then the hot-dip plating layer is removed with hydrochloric acid containing an inhibitor (for example, Hibiron manufactured by Sugimura Kagaku Kogyo Co., Ltd.). It can be determined by dissolving and subjecting the resulting solution to inductively coupled plasma (ICP) emission spectroscopic analysis. In addition, when there is no surface layer coating, the removal work of the surface layer coating can be omitted.
次に、溶融めっき層の組織について説明する。Ａｌ、Ｍｇ及びＺｎを含有する溶融めっき層は、〔Ａｌ相〕と、〔Ａｌ／Ｚｎ／ＭｇＺｎ２の三元共晶組織〕とを含んでいる。〔Ａｌ／Ｚｎ／ＭｇＺｎ２の三元共晶組織〕の素地中に、〔Ａｌ相〕が包含された形態を有している。更に、〔Ａｌ／Ｚｎ／ＭｇＺｎ２の三元共晶組織〕の素地中には、〔ＭｇＺｎ２相〕や〔Ｚｎ相〕が含まれる。また、Ｓｉを添加した場合には、〔Ａｌ／Ｚｎ／ＭｇＺｎ２の三元共晶組織〕の素地中に、〔Ｍｇ２Ｓｉ相〕が含まれていても良い。
Next, the structure of the hot-dip plating layer will be explained. The hot-dip plating layer containing Al, Mg, and Zn includes [Al phase] and [ternary eutectic structure of Al/Zn/MgZn 2 ]. It has a form in which the [Al phase] is included in the matrix of [ternary eutectic structure of Al/Zn/MgZn 2] . Furthermore, the matrix of [ternary eutectic structure of Al/Zn/MgZn 2] contains [MgZn 2 phase] and [Zn phase]. Moreover, when Si is added, [Mg 2 Si phase] may be included in the matrix of [ternary eutectic structure of Al/Zn/MgZn 2 ].
ここで、〔Ａｌ／Ｚｎ／ＭｇＺｎ２の三元共晶組織〕とは、Ａｌ相と、Ｚｎ相と金属間化合物ＭｇＺｎ２相との三元共晶組織であり、この三元共晶組織を形成しているＡｌ相は例えばＡｌ－Ｚｎ－Ｍｇの三元系平衡状態図における高温での「Ａｌ″相」（Ｚｎを固溶するＡｌ固溶体であり、少量のＭｇを含む）に相当するものである。この高温でのＡｌ″相は常温では通常は微細なＡｌ相と微細なＺｎ相に分離して現れる。また、該三元共晶組織中のＺｎ相は少量のＡｌを固溶し、場合によってはさらに少量のＭｇを固溶したＺｎ固溶体である。該三元共晶組織中のＭｇＺｎ２相は、Ｚｎ－Ｍｇの二元系平衡状態図のＺｎ：約８４質量％の付近に存在する金属間化合物相である。状態図で見る限りそれぞれの相にはその他の添加元素を固溶していないか、固溶していても極微量であると考えられるがその量は通常の分析では明確に区別できないため、この３つの相からなる三元共晶組織を本明細書では〔Ａｌ／Ｚｎ／ＭｇＺｎ２の三元共晶組織〕と表す。
Here, [ternary eutectic structure of Al/Zn/MgZn 2 ] is a ternary eutectic structure of an Al phase, a Zn phase, and an intermetallic compound MgZn 2 phase; The formed Al phase corresponds to, for example, the "Al" phase (an Al solid solution containing Zn and containing a small amount of Mg) at high temperature in the ternary equilibrium phase diagram of Al-Zn-Mg. It is. This Al'' phase at high temperature normally appears separated into a fine Al phase and a fine Zn phase at room temperature.Also, the Zn phase in the ternary eutectic structure dissolves a small amount of Al, and in some cases is a Zn solid solution containing a small amount of Mg.The MgZn two phase in the ternary eutectic structure is a metal that exists near Zn: about 84% by mass in the Zn-Mg binary equilibrium phase diagram. It is an intermediate compound phase.As can be seen from the phase diagram, each phase does not contain any other additive elements, or even if it does, it is considered to be in a very small amount, but the amount is clearly determined by normal analysis. Therefore, the ternary eutectic structure consisting of these three phases is herein referred to as [ternary eutectic structure of Al/Zn/MgZn 2 ].
また、〔Ａｌ相〕とは、前記の三元共晶組織の素地中に明瞭な境界をもって島状に見える相であり、これは例えばＡｌ－Ｚｎ－Ｍｇの三元系平衡状態図における高温での「Ａｌ″相」（Ｚｎを固溶するＡｌ固溶体であり、少量のＭｇを含む）に相当するものである。
この高温でのＡｌ″相はめっき浴のＡｌやＭｇ濃度に応じて固溶するＺｎ量やＭｇ量が相違する。この高温でのＡｌ″相は常温では通常は微細なＡｌ相と微細なＺｎ相に分離するが、常温で見られる島状の形状は高温でのＡｌ″相の形骸を留めたものであると見てよい。状態図で見る限りこの相にはその他の添加元素を固溶していないか、固溶していても極微量であると考えられるが通常の分析では明確に区別できないため、この高温でのＡｌ″相に由来し且つ形状的にはＡｌ″相の形骸を留めている相を本明細書では〔Ａｌ相〕と呼ぶ。この〔Ａｌ相〕は前記の三元共晶組織を形成しているＡｌ相とは顕微鏡観察において明瞭に区別できる。 Furthermore, the [Al phase] is a phase that appears like an island with clear boundaries in the matrix of the above-mentioned ternary eutectic structure; This corresponds to the "Al" phase (which is an Al solid solution containing Zn and a small amount of Mg).
The amount of dissolved Zn and Mg in this Al'' phase at high temperature differs depending on the Al and Mg concentrations in the plating bath.At room temperature, this Al'' phase at high temperature is usually composed of a fine Al phase and a fine Zn phase. It separates into phases, but the island-like shape seen at room temperature can be considered to be the remains of the Al'' phase at high temperatures.As far as we can see from the phase diagram, this phase contains other additive elements as a solid solution. It is thought that the Al'' phase is derived from the Al'' phase at this high temperature, and that the shape is only a trace of the Al'' phase. The phase that is retained is referred to herein as the [Al phase]. This [Al phase] can be clearly distinguished from the Al phase forming the ternary eutectic structure described above by microscopic observation.
この高温でのＡｌ″相はめっき浴のＡｌやＭｇ濃度に応じて固溶するＺｎ量やＭｇ量が相違する。この高温でのＡｌ″相は常温では通常は微細なＡｌ相と微細なＺｎ相に分離するが、常温で見られる島状の形状は高温でのＡｌ″相の形骸を留めたものであると見てよい。状態図で見る限りこの相にはその他の添加元素を固溶していないか、固溶していても極微量であると考えられるが通常の分析では明確に区別できないため、この高温でのＡｌ″相に由来し且つ形状的にはＡｌ″相の形骸を留めている相を本明細書では〔Ａｌ相〕と呼ぶ。この〔Ａｌ相〕は前記の三元共晶組織を形成しているＡｌ相とは顕微鏡観察において明瞭に区別できる。 Furthermore, the [Al phase] is a phase that appears like an island with clear boundaries in the matrix of the above-mentioned ternary eutectic structure; This corresponds to the "Al" phase (which is an Al solid solution containing Zn and a small amount of Mg).
The amount of dissolved Zn and Mg in this Al'' phase at high temperature differs depending on the Al and Mg concentrations in the plating bath.At room temperature, this Al'' phase at high temperature is usually composed of a fine Al phase and a fine Zn phase. It separates into phases, but the island-like shape seen at room temperature can be considered to be the remains of the Al'' phase at high temperatures.As far as we can see from the phase diagram, this phase contains other additive elements as a solid solution. It is thought that the Al'' phase is derived from the Al'' phase at this high temperature, and that the shape is only a trace of the Al'' phase. The phase that is retained is referred to herein as the [Al phase]. This [Al phase] can be clearly distinguished from the Al phase forming the ternary eutectic structure described above by microscopic observation.
また、〔Ｚｎ相〕とは、前記の三元共晶組織の素地中に明瞭な境界をもって島状に見える相であり、実際には少量のＡｌさらには少量のＭｇを固溶していることもある。状態図で見る限りこの相にはその他の添加元素を固溶していないか、固溶していても極微量であると考えられる。この〔Ｚｎ相〕は円相当直径で２．５μｍ以上となる領域であり、前記の三元共晶組織を形成しているＺｎ相とは顕微鏡観察において明瞭に区別できる。
Furthermore, the [Zn phase] is a phase that appears like an island with clear boundaries in the matrix of the above-mentioned ternary eutectic structure, and it actually contains a small amount of Al and even a small amount of Mg. There is also. As far as we can see from the phase diagram, it is thought that other additive elements are not dissolved in this phase, or even if they are dissolved, the amount is extremely small. This [Zn phase] is a region having an equivalent circle diameter of 2.5 μm or more, and can be clearly distinguished from the Zn phase forming the above-mentioned ternary eutectic structure by microscopic observation.
また、〔ＭｇＺｎ２相〕とは、前記の三元共晶組織の素地中に明瞭な境界をもって島状に見える相であり、実際には少量のＡｌを固溶していることもある。状態図で見る限りこの相にはその他の添加元素を固溶していないか、固溶していても極微量であると考えられる。この〔ＭｇＺｎ２相〕は前記の三元共晶組織を形成しているＭｇＺｎ２相とは顕微鏡観察において明瞭に区別できる。本発明のめっき層には、製造条件により〔ＭｇＺｎ２相〕が含まれない場合も有るが、ほとんどの製造条件ではめっき層中に含まれる。
Further, [MgZn two phase] is a phase that appears like an island with clear boundaries in the matrix of the above-mentioned ternary eutectic structure, and may actually contain a small amount of Al in solid solution. As far as we can see from the phase diagram, it is considered that other additive elements are not dissolved in this phase, or even if they are dissolved, the amount is extremely small. This [MgZn two- phase] can be clearly distinguished from the MgZn two- phase forming the above-mentioned ternary eutectic structure by microscopic observation. The plating layer of the present invention may not contain [MgZn two -phase] depending on the manufacturing conditions, but it is contained in the plating layer under most manufacturing conditions.
また、〔Ｍｇ２Ｓｉ相〕とは、Ｓｉを添加した場合のめっき層の凝固組織中に明瞭な境界をもって島状に見える相である。状態図で見る限りＺｎ、Ａｌ、その他の添加元素は固溶していないか、固溶していても極微量であると考えられる。この〔Ｍｇ２Ｓｉ相〕はめっき中では顕微鏡観察において明瞭に区別できる。
Moreover, [Mg 2 Si phase] is a phase that appears in the form of islands with clear boundaries in the solidified structure of the plating layer when Si is added. As far as we can see from the phase diagram, it is thought that Zn, Al, and other additive elements are not dissolved in solid solution, or even if they are dissolved in solid solution, the amount is extremely small. This [Mg 2 Si phase] can be clearly distinguished by microscopic observation during plating.
次に、溶融めっき層の表層におけるパターン部、非パターン部、第１領域及び第２領域について説明する。
Next, the pattern portion, non-pattern portion, first region, and second region in the surface layer of the hot-dip plating layer will be explained.
本実施形態の溶融めっき層の表面には、パターン部と、非パターン部とが形成される。パターン部の美観を確保する観点から、パターン部は所定の形状となるように配置されることが好ましい。また、パターン部の視認性を確保する観点から、パターン部のサイズは大きいほど好ましい。例えば、パターン部が、人工的な形状を有することが好ましい。パターン部は、意図的な形状に配置されていることが好ましい。パターン部は、直線部、曲線部、ドット部、図形、数字、記号若しくは文字のいずれか１種またはこれらのうちの２種以上を組合せた形状となるように配置されていることが好ましい。例えば、溶融めっき層の表面には、パターン部からなる文字列、数字列、記号、マーク、線図、デザイン画あるいはこれらの組合せ等が現される。パターン部における直線部や曲線部はそれぞれ１ｍｍ以上の長さであることが好ましい。これらのような形状を示すことでパターン部は、意図的に形成されたと言える。パターン部における直線部や曲線部は、後述するような目視で認識できる程度の幅を有し、かつそれぞれ１ｍｍ以上の長さであることが好ましい。パターン部におけるドット部は円相当直径１ｍｍ以上１０ｍｍ未満であることが好ましく、複数のドット部が規則正しく配列されることが更に好ましい。また、パターン部が、図形、数字、記号、模様若しくは文字である場合には、これらの形状が後述するような目視で認識できることが好ましい。このような寸法及び形状を示すことで更に意図的に形成されたと言える。また、非パターン部は、パターン部以外の領域である。パターン部の形状は、ドット抜けのように一部が欠けていても、全体として認識できれば、許容される。非パターン部はパターン部の境界を縁取るような形状であってもよい。
A patterned portion and a non-patterned portion are formed on the surface of the hot-dip plating layer of this embodiment. From the viewpoint of ensuring the aesthetic appearance of the pattern portion, it is preferable that the pattern portion be arranged to have a predetermined shape. Further, from the viewpoint of ensuring the visibility of the pattern section, the larger the size of the pattern section, the more preferable. For example, it is preferable that the pattern portion has an artificial shape. Preferably, the pattern portions are arranged in an intentional shape. It is preferable that the pattern portions are arranged to have a shape of any one of a straight line portion, a curved portion, a dot portion, a figure, a number, a symbol, or a character, or a combination of two or more of these. For example, on the surface of the hot-dip plating layer, a string of characters, a string of numbers, a symbol, a mark, a diagram, a design drawing, or a combination thereof consisting of a pattern portion appears. It is preferable that the straight portions and curved portions in the pattern portion each have a length of 1 mm or more. By exhibiting these shapes, it can be said that the pattern portion was intentionally formed. It is preferable that the straight line portions and curved portions in the pattern portion have a width that can be visually recognized as described below, and each have a length of 1 mm or more. The dot portions in the pattern portion preferably have an equivalent circle diameter of 1 mm or more and less than 10 mm, and more preferably a plurality of dot portions are regularly arranged. Moreover, when the pattern portion is a figure, number, symbol, pattern, or character, it is preferable that the shape of these can be visually recognized as described below. By showing such dimensions and shape, it can be said that the shape was intentionally formed. Furthermore, the non-pattern portion is an area other than the pattern portion. Even if a part of the pattern part is missing, such as a missing dot, it is acceptable as long as it can be recognized as a whole. The non-patterned portion may have a shape that borders the patterned portion.
溶融めっき層表面に、直線部、曲線部、ドット部、図形、数字、記号若しくは文字のいずれか１種またはこれらのうちの２種以上を組合せた形状が配置されている場合に、これらの領域をパターン部とし、それ以外の領域を非パターン部とすることができる。この形状は、後述する製造方法によって意図的若しくは人工的に形成された形状であり、自然に形成されたものではない。
パターン部と非パターン部の境界は、肉眼で把握することができる。パターン部と非パターン部の境界は、光学顕微鏡や拡大鏡などによる拡大像から把握してもよい。 If the surface of the hot-dip plating layer is arranged with any one of straight parts, curved parts, dotted parts, figures, numbers, symbols, or characters, or a combination of two or more of these, these areas can be made into a pattern part, and the other area can be made into a non-pattern part. This shape is intentionally or artificially formed by a manufacturing method described below, and is not naturally formed.
The boundary between the pattern portion and the non-pattern portion can be recognized with the naked eye. The boundary between the pattern portion and the non-pattern portion may be determined from an enlarged image using an optical microscope, a magnifying glass, or the like.
パターン部と非パターン部の境界は、肉眼で把握することができる。パターン部と非パターン部の境界は、光学顕微鏡や拡大鏡などによる拡大像から把握してもよい。 If the surface of the hot-dip plating layer is arranged with any one of straight parts, curved parts, dotted parts, figures, numbers, symbols, or characters, or a combination of two or more of these, these areas can be made into a pattern part, and the other area can be made into a non-pattern part. This shape is intentionally or artificially formed by a manufacturing method described below, and is not naturally formed.
The boundary between the pattern portion and the non-pattern portion can be recognized with the naked eye. The boundary between the pattern portion and the non-pattern portion may be determined from an enlarged image using an optical microscope, a magnifying glass, or the like.
パターン部は、肉眼、拡大鏡下または顕微鏡下でパターン部の存在を判別可能な程度の大きさに形成されるとよい。また、非パターン部は、溶融めっき層（溶融めっき層の表面）の大部分を占める領域である。
パターン部は、非パターン部内に配置されている。具体的には、パターン部は、非パターン部内において、直線部、曲線部、図形、ドット部、図形、数字、記号若しくは文字のいずれか１種またはこれらのうちの２種以上を組合せた形状となるように配置されている。パターン部の形状を調整することによって、溶融めっき層の表面に、直線部、曲線部、図形、ドット部、図形、数字、記号若しくは文字のいずれか１種またはこれらのうちの２種以上を組合せた形状が現される。例えば、溶融めっき層の表面には、パターン部からなる文字列、数字列、記号、マーク、線図、デザイン画あるいはこれらの組合せ等が現される。この形状は、後述する製造方法によって意図的若しくは人工的に形成された形状であり、自然に形成されたものではない。通常の溶融めっき層の外観を知る当業者であれば、人為的形状を有するパターン部と非パターン部とを容易に区別することができる。
なお、パターン部の視認性を向上させる観点から、パターン部が溶融めっき層の表面に占める面積率が、非パターン部よりも大幅に小さいことが好ましい。例えば、パターン部が溶融めっき層の表面に占める面積率が、３０％以下、２５％以下、２０％以下、又は１５％以下であることが好ましい。 The pattern portion is preferably formed to a size that allows the presence of the pattern portion to be determined with the naked eye, under a magnifying glass, or under a microscope. Further, the non-patterned portion is a region that occupies most of the hot-dip plating layer (the surface of the hot-dip plating layer).
The pattern section is arranged within the non-pattern section. Specifically, the pattern part has a shape in the non-pattern part of any one of a straight line part, a curved part, a figure, a dot part, a figure, a number, a symbol, or a character, or a combination of two or more of these. It is arranged so that By adjusting the shape of the pattern part, any one of straight parts, curved parts, figures, dot parts, figures, numbers, symbols, or characters, or two or more of these can be combined on the surface of the hot-dip plating layer. A new shape appears. For example, on the surface of the hot-dip plating layer, a string of characters, a string of numbers, a symbol, a mark, a diagram, a design drawing, or a combination thereof consisting of a pattern portion appears. This shape is intentionally or artificially formed by a manufacturing method described below, and is not naturally formed. A person skilled in the art who knows the appearance of a normal hot-dip plating layer can easily distinguish between a patterned portion having an artificial shape and a non-patterned portion.
In addition, from the viewpoint of improving the visibility of the pattern part, it is preferable that the area ratio occupied by the pattern part on the surface of the hot-dip plating layer is significantly smaller than that of the non-pattern part. For example, it is preferable that the area ratio occupied by the pattern portion on the surface of the hot-dip plating layer is 30% or less, 25% or less, 20% or less, or 15% or less.
パターン部は、非パターン部内に配置されている。具体的には、パターン部は、非パターン部内において、直線部、曲線部、図形、ドット部、図形、数字、記号若しくは文字のいずれか１種またはこれらのうちの２種以上を組合せた形状となるように配置されている。パターン部の形状を調整することによって、溶融めっき層の表面に、直線部、曲線部、図形、ドット部、図形、数字、記号若しくは文字のいずれか１種またはこれらのうちの２種以上を組合せた形状が現される。例えば、溶融めっき層の表面には、パターン部からなる文字列、数字列、記号、マーク、線図、デザイン画あるいはこれらの組合せ等が現される。この形状は、後述する製造方法によって意図的若しくは人工的に形成された形状であり、自然に形成されたものではない。通常の溶融めっき層の外観を知る当業者であれば、人為的形状を有するパターン部と非パターン部とを容易に区別することができる。
なお、パターン部の視認性を向上させる観点から、パターン部が溶融めっき層の表面に占める面積率が、非パターン部よりも大幅に小さいことが好ましい。例えば、パターン部が溶融めっき層の表面に占める面積率が、３０％以下、２５％以下、２０％以下、又は１５％以下であることが好ましい。 The pattern portion is preferably formed to a size that allows the presence of the pattern portion to be determined with the naked eye, under a magnifying glass, or under a microscope. Further, the non-patterned portion is a region that occupies most of the hot-dip plating layer (the surface of the hot-dip plating layer).
The pattern section is arranged within the non-pattern section. Specifically, the pattern part has a shape in the non-pattern part of any one of a straight line part, a curved part, a figure, a dot part, a figure, a number, a symbol, or a character, or a combination of two or more of these. It is arranged so that By adjusting the shape of the pattern part, any one of straight parts, curved parts, figures, dot parts, figures, numbers, symbols, or characters, or two or more of these can be combined on the surface of the hot-dip plating layer. A new shape appears. For example, on the surface of the hot-dip plating layer, a string of characters, a string of numbers, a symbol, a mark, a diagram, a design drawing, or a combination thereof consisting of a pattern portion appears. This shape is intentionally or artificially formed by a manufacturing method described below, and is not naturally formed. A person skilled in the art who knows the appearance of a normal hot-dip plating layer can easily distinguish between a patterned portion having an artificial shape and a non-patterned portion.
In addition, from the viewpoint of improving the visibility of the pattern part, it is preferable that the area ratio occupied by the pattern part on the surface of the hot-dip plating layer is significantly smaller than that of the non-pattern part. For example, it is preferable that the area ratio occupied by the pattern portion on the surface of the hot-dip plating layer is 30% or less, 25% or less, 20% or less, or 15% or less.
このように、パターン部及び非パターン部は、溶融めっき層の表面に形成された領域であり、また、パターン部及び非パターン部には、それぞれ、第１領域、第２領域のうちの１種または２種が含まれる。
In this way, the pattern part and the non-pattern part are regions formed on the surface of the hot-dip plating layer, and the pattern part and the non-pattern part each include one type of the first region and the second region. Or two types are included.
第１領域は、比率（Ｂ／Ａ（％））が２０％以上の領域であるため、溶融めっき層において第１領域が多い箇所は、白色もしくは白色に近い色に見える。一方、第２領域は、比率（Ｂ／Ａ（％））が２０％未満の領域であるため、溶融めっき層において第２領域が多い箇所は、金属光沢があるように見える。また、第１領域と第２領域がそれぞれ分散して集まり、第１領域の面積率が３０～７０％である箇所は、外観が梨地状に見える。
Since the first region is a region where the ratio (B/A (%)) is 20% or more, areas in the hot-dip plating layer where the first region is large appear white or a color close to white. On the other hand, since the second region has a ratio (B/A (%)) of less than 20%, areas in the hot-dip plating layer where the second region is large appear to have metallic luster. Further, in areas where the first area and the second area are dispersed and gathered together, and the area ratio of the first area is 30 to 70%, the appearance appears satin-like.
第１領域および第２領域は、次のように決定される。溶融めっき層の厚みをｔとして、溶融めっき層の表面から３ｔ／４位置、ｔ／２位置またはｔ／４位置のいずれかの位置において、表面２ａに平行でかつ、平面視において１～５ｍｍ四方の正方形状の露出面３、４、又は５が現れるように、溶融めっき層を切り欠く。これにより、溶融めっき層の表面に平行な１～５ｍｍ四方の露出面（断面）を形成する。各露出面に０．５ｍｍ間隔で仮想格子線を描く。仮想格子線によって区画される複数の領域においてそれぞれ、〔Ｚｎ相〕および〔Ａｌ／ＭｇＺｎ２／Ｚｎの三元共晶組織〕の合計面積分率Ａに対する〔Ｚｎ相〕の面積分率Ｂの比率（Ｂ／Ａ（％））が２０％以上になる領域を第１領域とし、比率（Ｂ／Ａ（％））が２０％未満となる領域を第２領域とする。
The first area and the second area are determined as follows. Assuming the thickness of the hot-dip plating layer is t, at any position of 3t/4, t/2 or t/4 from the surface of the hot-dip plating layer, parallel to the surface 2a and 1 to 5 mm square in plan view. The hot-dip plating layer is cut out so that a square-shaped exposed surface 3, 4, or 5 is exposed. This forms an exposed surface (cross section) of 1 to 5 mm square parallel to the surface of the hot-dip plating layer. Draw virtual grid lines at 0.5 mm intervals on each exposed surface. Ratio of area fraction B of [Zn phase] to total area fraction A of [Zn phase] and [ternary eutectic structure of Al/MgZn 2 /Zn] in a plurality of regions partitioned by virtual lattice lines, respectively. A region where the ratio (B/A (%)) is 20% or more is defined as a first region, and a region where the ratio (B/A (%)) is less than 20% is defined as a second region.
以下、第１領域および第２領域の具体的な決定方法について説明する。
図１及び図２に示すように、鋼板１上に形成された溶融めっき層２の厚みをｔとし、溶融めっき層２の表面２ａから３ｔ／４位置、ｔ／２位置またはｔ／４位置のいずれかの位置において表面に平行な１～５ｍｍ四方の露出面３、４、又は５を形成する。なお、パターン部及び／又は非パターン部の内部に５ｍｍ四方の露出面が形成できない程度にパターン部及び／又は非パターン部が小さい場合は、露出面の形状を最小で１ｍｍ四方としてもよい。この場合、露出面の数を増大させることにより、測定用の領域の面積を確保する。 A specific method for determining the first area and the second area will be described below.
As shown in FIGS. 1 and 2, the thickness of the hot-dip plating layer 2 formed on the steel plate 1 is t, and the positions 3t/4, t/2, or t/4 from the surface 2a of the hot-dip plating layer 2 are At any position, an exposed surface 3, 4, or 5 of 1 to 5 mm square is formed parallel to the surface. Note that if the patterned portion and/or non-patterned portion is so small that an exposed surface of 5 mm square cannot be formed inside the patterned portion and/or non-patterned portion, the shape of the exposed surface may be at least 1 mm square. In this case, by increasing the number of exposed surfaces, the area of the measurement region is secured.
図１及び図２に示すように、鋼板１上に形成された溶融めっき層２の厚みをｔとし、溶融めっき層２の表面２ａから３ｔ／４位置、ｔ／２位置またはｔ／４位置のいずれかの位置において表面に平行な１～５ｍｍ四方の露出面３、４、又は５を形成する。なお、パターン部及び／又は非パターン部の内部に５ｍｍ四方の露出面が形成できない程度にパターン部及び／又は非パターン部が小さい場合は、露出面の形状を最小で１ｍｍ四方としてもよい。この場合、露出面の数を増大させることにより、測定用の領域の面積を確保する。 A specific method for determining the first area and the second area will be described below.
As shown in FIGS. 1 and 2, the thickness of the hot-
これらの露出面３、４、又は５を形成する際には、研削やアルゴンスパッタ等の手段により、溶融めっき層を削り取る。また、露出面は鏡面とすることが望ましく、例えば露出面の最大高さＲｚを０．２μｍ以下とすることが望ましい。観察対象とする露出面は、溶融めっき層表面から３ｔ／４位置、ｔ／２位置またはｔ／４位置のいずれの露出面であってもよい。好ましくはｔ／２位置の露出面を選択してもよい。ｔ／２位置の露出面において求められたＢ／Ａ比率は、他の位置においても同等の値をとる可能性が高い。
When forming these exposed surfaces 3, 4, or 5, the hot-dip plating layer is scraped off by means such as grinding or argon sputtering. Further, it is desirable that the exposed surface be a mirror surface, and for example, it is desirable that the maximum height Rz of the exposed surface be 0.2 μm or less. The exposed surface to be observed may be any exposed surface at 3t/4 position, t/2 position, or t/4 position from the surface of the hot-dip plating layer. Preferably, the exposed surface at the t/2 position may be selected. The B/A ratio determined on the exposed surface at the t/2 position is likely to take a similar value at other positions.
次いで、図３に示されるように、観察対象とする露出面に、０．５ｍｍ間隔で仮想格子線を描き、仮想格子線によって区画される複数の領域においてそれぞれ、比率（Ｂ／Ａ（％））を測定する。
比率（Ｂ／Ａ（％））が２０％以上の領域が第１領域となり、比率（Ｂ／Ａ（％））が２０％未満の領域が第２領域となる。 Next, as shown in FIG. 3, virtual grid lines are drawn at 0.5 mm intervals on the exposed surface to be observed, and the ratio (B/A (%) ) to measure.
The area where the ratio (B/A (%)) is 20% or more is the first area, and the area where the ratio (B/A (%)) is less than 20% is the second area.
比率（Ｂ／Ａ（％））が２０％以上の領域が第１領域となり、比率（Ｂ／Ａ（％））が２０％未満の領域が第２領域となる。 Next, as shown in FIG. 3, virtual grid lines are drawn at 0.5 mm intervals on the exposed surface to be observed, and the ratio (B/A (%) ) to measure.
The area where the ratio (B/A (%)) is 20% or more is the first area, and the area where the ratio (B/A (%)) is less than 20% is the second area.
比率（Ｂ／Ａ（％））の測定は、次のようにして行う。走査型電子顕微鏡（ＳＥＭ）の二次電子像により、領域毎にめっき組織を観察して、〔Ｚｎ相〕および〔Ａｌ／ＭｇＺｎ２／Ｚｎの三元共晶組織〕を特定する。各相および組織を特定する際は、ＳＥＭに付属するエネルギー分散型Ｘ線元素分析装置による元素分析を併用し、Ｚｎ、ＡｌおよびＭｇの分布を確認しつつ特定する。そして、〔Ｚｎ相〕および〔Ａｌ／ＭｇＺｎ２／Ｚｎの三元共晶組織〕の合計面積分率Ａに対する〔Ｚｎ相〕の面積分率Ｂの比率（Ｂ／Ａ（％））を求める。〔Ｚｎ相〕は、円相当直径で２．５μｍ以上となる領域のものを〔Ｚｎ相〕として計測する。これにより、〔Ａｌ／ＭｇＺｎ２／Ｚｎの三元共晶組織〕中のＺｎ相と〔Ｚｎ相〕とを区別する。
The ratio (B/A (%)) is measured as follows. The plating structure is observed for each region using a secondary electron image using a scanning electron microscope (SEM), and the [Zn phase] and the [ternary eutectic structure of Al/MgZn 2 /Zn] are identified. When specifying each phase and structure, elemental analysis by an energy dispersive X-ray elemental analyzer attached to the SEM is used in combination, and the distributions of Zn, Al, and Mg are confirmed and specified. Then, the ratio (B/A (%)) of the area fraction B of [Zn phase] to the total area fraction A of [Zn phase] and [ternary eutectic structure of Al/MgZn 2 /Zn] is determined. [Zn phase] is measured as [Zn phase] in a region where the equivalent circle diameter is 2.5 μm or more. Thereby, the Zn phase in the [ternary eutectic structure of Al/MgZn 2 /Zn] is distinguished from the [Zn phase].
パターン部には、仮想格子線によって区画された複数の領域が含まれており、各領域は、第１領域、第２領域の何れかに分類される。また、非パターン部にも、仮想格子線によって区画された複数の領域が含まれており、各領域は、第１領域、第２領域のいずれかに分類される。すなわち、パターン部は、第１領域、第２領域のいずれかのみを含んでいてもよく、第１領域、第２領域の２種を含んでいてもよい。同様に、非パターン部は、第１領域、第２領域のいずれかのみを含んでいてもよく、第１領域、第２領域の２種を含んでいてもよい。
The pattern section includes a plurality of regions divided by virtual grid lines, and each region is classified as either a first region or a second region. Further, the non-pattern portion also includes a plurality of regions partitioned by virtual grid lines, and each region is classified as either a first region or a second region. That is, the pattern section may include only either the first area or the second area, or may include two types of the first area and the second area. Similarly, the non-pattern portion may include only either the first region or the second region, or may include two types, the first region and the second region.
ここで、パターン部においては、第１領域及び第２領域のそれぞれの面積割合を求めることができる。そして、第１領域の面積分率が７０％を超える場合は、パターン部が白色もしくは白色に近い色に見える。第１領域の面積分率が３０％以上７０％以下である場合は、パターン部が梨地状に見える。また、第１領域の面積分率が３０％未満である場合、パターン部は金属光沢があるように見える。このように、パターン部の外観は、第１領域の面積分率に依存する。
Here, in the pattern portion, the area ratio of each of the first region and the second region can be determined. When the area fraction of the first region exceeds 70%, the pattern portion appears white or a color close to white. When the area fraction of the first region is 30% or more and 70% or less, the pattern portion appears satin-like. Further, when the area fraction of the first region is less than 30%, the pattern portion appears to have metallic luster. In this way, the appearance of the pattern portion depends on the area fraction of the first region.
一方、非パターン部においても、第１領域及び第２領域のそれぞれの面積割合を求めることができる。パターン部と同様、非パターン部の外観は、第１領域の面積分率に依存する。
On the other hand, also in the non-patterned part, the area ratio of each of the first region and the second region can be determined. Similar to the patterned portion, the appearance of the non-patterned portion depends on the area fraction of the first region.
そして、パターン部における第１領域の面積割合と、非パターン部における第１領域の面積割合との差が、絶対値で３０％以上の場合に、パターン部と非パターン部とを識別できるようになる。面積割合の差が３０％未満では、パターン部における第１領域の面積割合と、非パターン部における第１領域の面積割合との差が小さく、パターン部及び非パターン部の外観が似たような外観になり、パターン部を識別することが困難になる。面積割合の差は、大きければ大きいほどよく、４０％以上であることがより好ましく、６０％以上であることが更に好ましい。
Then, when the difference between the area ratio of the first region in the pattern part and the area ratio of the first region in the non-pattern part is 30% or more in absolute value, the pattern part and the non-pattern part can be distinguished. Become. When the difference in area ratio is less than 30%, the difference between the area ratio of the first region in the pattern part and the area ratio of the first region in the non-pattern part is small, and the appearance of the pattern part and the non-pattern part are similar. This makes it difficult to identify the pattern part. The larger the difference in area ratio, the better; it is more preferably 40% or more, and even more preferably 60% or more.
パターン部及び非パターン部は、肉眼で識別可能であってもよく、拡大鏡下または顕微鏡下で目視で識別可能であってもよい。拡大鏡下または顕微鏡下で目視で識別可能とは、例えば、パターン部で構成される形状が５０倍以下の視野で目視で識別可能であればよい。パターン部は人為的な所定の形状を有するので、５０倍以下の視野であれば、パターン部と非パターン部は、その外観の違いにより、識別可能である。パターン部と非パターン部は、好ましくは２０倍以下、さらに好ましくは１０倍以下、より好ましくは５倍以下で識別可能である。
本実施形態に係る溶融めっき鋼板は、溶融めっき層の表面に化成処理皮膜層や塗膜層を有してもよい。ここで、化成処理皮膜層や塗膜層の種類は特に限定されず、公知の化成処理皮膜層や塗膜層を用いることができる。 The patterned portions and non-patterned portions may be discernible with the naked eye, or may be visually discernible under a magnifying glass or a microscope. The phrase "visually discernible under a magnifying glass or a microscope" means, for example, that the shape formed by the pattern section can be visually discerned under a field of view of 50 times or less. Since the pattern portion has an artificial predetermined shape, the pattern portion and the non-pattern portion can be distinguished from each other by the difference in their appearance if the field of view is 50 times or less. The pattern portion and the non-pattern portion can be distinguished preferably at a magnification of 20 times or less, more preferably at a magnification of 10 times or less, and even more preferably at a magnification of 5 times or less.
The hot-dip plated steel sheet according to this embodiment may have a chemical conversion coating layer or a coating layer on the surface of the hot-dip plated layer. Here, the type of the chemical conversion coating layer or coating layer is not particularly limited, and any known chemical conversion coating layer or coating layer can be used.
本実施形態に係る溶融めっき鋼板は、溶融めっき層の表面に化成処理皮膜層や塗膜層を有してもよい。ここで、化成処理皮膜層や塗膜層の種類は特に限定されず、公知の化成処理皮膜層や塗膜層を用いることができる。 The patterned portions and non-patterned portions may be discernible with the naked eye, or may be visually discernible under a magnifying glass or a microscope. The phrase "visually discernible under a magnifying glass or a microscope" means, for example, that the shape formed by the pattern section can be visually discerned under a field of view of 50 times or less. Since the pattern portion has an artificial predetermined shape, the pattern portion and the non-pattern portion can be distinguished from each other by the difference in their appearance if the field of view is 50 times or less. The pattern portion and the non-pattern portion can be distinguished preferably at a magnification of 20 times or less, more preferably at a magnification of 10 times or less, and even more preferably at a magnification of 5 times or less.
The hot-dip plated steel sheet according to this embodiment may have a chemical conversion coating layer or a coating layer on the surface of the hot-dip plated layer. Here, the type of the chemical conversion coating layer or coating layer is not particularly limited, and any known chemical conversion coating layer or coating layer can be used.
以上、本発明の第一実施形態に係る溶融めっき鋼板について説明した。次に本発明の第二実施形態に係る溶融めっき鋼板について説明する。第二実施形態に係る溶融めっき鋼板は、鋼板と、鋼板の表面に形成された溶融めっき層と、を備え、溶融めっき層は、平均組成で、Ａｌ：５～２２質量％、Ｍｇ：１．０～１０質量％を含有し、残部がＺｎおよび不純物を含み、溶融めっき層の表面は、下記の測定方法で得られる第１領域、第２領域のうちの１種または２種を含み、１．０ｍｍ四方以上の領域である第１部分における第１領域の面積率と、第１部分に隣接する１．０ｍｍ四方以上の領域である第２部分における第１領域の面積率との差の絶対値が、３０％以上である。
［測定方法］
溶融めっき層の厚みをｔとして、溶融めっき層の表面から３ｔ／４位置、ｔ／２位置またはｔ／４位置のいずれかの位置において表面に平行な１～５ｍｍ四方の断面を露出させ、各断面に０．５ｍｍ間隔で仮想格子線を描き、仮想格子線によって区画される複数の領域においてそれぞれ、〔Ｚｎ相〕および〔Ａｌ／ＭｇＺｎ２／Ｚｎの三元共晶組織〕の合計面積分率Ａに対する〔Ｚｎ相〕の面積分率Ｂの比率（Ｂ／Ａ（％））が２０％以上になる領域を第１領域とし、比率（Ｂ／Ａ（％））が２０％未満となる領域を第２領域とする。
第二実施形態に係る溶融めっき鋼板の鋼板、及び溶融めっき層の成分は、第一実施形態に係る溶融めっき鋼板と同じである。
第二実施形態に係る溶融めっき鋼板においては、１．０ｍｍ四方以上の領域である第１部分における第１領域の面積率と、第１部分に隣接する１．０ｍｍ四方以上の領域である第２部分における第１領域の面積率との差の絶対値が、３０％以上とされる。ここで、「１．０ｍｍ四方以上の領域」とは、１．０ｍｍ四方の正方形よりも大きい領域のことをいう。１．０ｍｍ四方の正方形の全体をその内部に包含可能な領域は、「１．０ｍｍ四方以上の領域」である。この特徴点によれば、第一部分及び第二部分を、肉眼によって明瞭に識別可能である。第一部分及び第二部分を任意の形状にすることにより、めっき層の表面に文字やデザイン等を現すことができる。 The hot-dip galvanized steel sheet according to the first embodiment of the present invention has been described above. Next, a hot-dipped steel plate according to a second embodiment of the present invention will be described. The hot-dip plated steel plate according to the second embodiment includes a steel plate and a hot-dip plated layer formed on the surface of the steel plate, and the average composition of the hot-dip plated layer is Al: 5 to 22% by mass, Mg: 1. 0 to 10% by mass, the remainder containing Zn and impurities, the surface of the hot-dip plating layer includes one or two of the first region and second region obtained by the following measurement method, Absolute difference between the area ratio of the first region in the first part, which is an area of .0 mm square or more, and the area ratio of the first region in the second part, which is an area of 1.0 mm square or more adjacent to the first part. The value is 30% or more.
[Measuring method]
Letting the thickness of the hot-dip plating layer be t, expose a 1 to 5 mm square cross section parallel to the surface at any position of 3t/4, t/2 or t/4 from the surface of the hot-dip plating layer, and Virtual grid lines are drawn on the cross section at 0.5 mm intervals, and the total area fraction A of [Zn phase] and [ternary eutectic structure of Al/MgZn2/Zn] is calculated in each of multiple regions partitioned by the virtual grid lines. The area where the ratio (B/A (%)) of the area fraction B of [Zn phase] is 20% or more is defined as the first area, and the area where the ratio (B/A (%)) is less than 20% is defined as the first area. This is the second area.
The components of the steel plate and the hot-dip coating layer of the hot-dip plated steel plate according to the second embodiment are the same as those of the hot-dip plated steel plate according to the first embodiment.
In the hot-dip galvanized steel sheet according to the second embodiment, the area ratio of the first region in the first portion is an area of 1.0 mm square or more, and the area ratio of the first region is an area of 1.0 mm square or more adjacent to the first portion. The absolute value of the difference between the portion and the area ratio of the first region is 30% or more. Here, "an area of 1.0 mm square or more" refers to an area larger than a 1.0 mm square. The area that can include the entire 1.0 mm square is "an area larger than or equal to 1.0 mm square." According to this characteristic point, the first portion and the second portion can be clearly identified with the naked eye. By forming the first portion and the second portion into arbitrary shapes, letters, designs, etc. can be displayed on the surface of the plating layer.
［測定方法］
溶融めっき層の厚みをｔとして、溶融めっき層の表面から３ｔ／４位置、ｔ／２位置またはｔ／４位置のいずれかの位置において表面に平行な１～５ｍｍ四方の断面を露出させ、各断面に０．５ｍｍ間隔で仮想格子線を描き、仮想格子線によって区画される複数の領域においてそれぞれ、〔Ｚｎ相〕および〔Ａｌ／ＭｇＺｎ２／Ｚｎの三元共晶組織〕の合計面積分率Ａに対する〔Ｚｎ相〕の面積分率Ｂの比率（Ｂ／Ａ（％））が２０％以上になる領域を第１領域とし、比率（Ｂ／Ａ（％））が２０％未満となる領域を第２領域とする。
第二実施形態に係る溶融めっき鋼板の鋼板、及び溶融めっき層の成分は、第一実施形態に係る溶融めっき鋼板と同じである。
第二実施形態に係る溶融めっき鋼板においては、１．０ｍｍ四方以上の領域である第１部分における第１領域の面積率と、第１部分に隣接する１．０ｍｍ四方以上の領域である第２部分における第１領域の面積率との差の絶対値が、３０％以上とされる。ここで、「１．０ｍｍ四方以上の領域」とは、１．０ｍｍ四方の正方形よりも大きい領域のことをいう。１．０ｍｍ四方の正方形の全体をその内部に包含可能な領域は、「１．０ｍｍ四方以上の領域」である。この特徴点によれば、第一部分及び第二部分を、肉眼によって明瞭に識別可能である。第一部分及び第二部分を任意の形状にすることにより、めっき層の表面に文字やデザイン等を現すことができる。 The hot-dip galvanized steel sheet according to the first embodiment of the present invention has been described above. Next, a hot-dipped steel plate according to a second embodiment of the present invention will be described. The hot-dip plated steel plate according to the second embodiment includes a steel plate and a hot-dip plated layer formed on the surface of the steel plate, and the average composition of the hot-dip plated layer is Al: 5 to 22% by mass, Mg: 1. 0 to 10% by mass, the remainder containing Zn and impurities, the surface of the hot-dip plating layer includes one or two of the first region and second region obtained by the following measurement method, Absolute difference between the area ratio of the first region in the first part, which is an area of .0 mm square or more, and the area ratio of the first region in the second part, which is an area of 1.0 mm square or more adjacent to the first part. The value is 30% or more.
[Measuring method]
Letting the thickness of the hot-dip plating layer be t, expose a 1 to 5 mm square cross section parallel to the surface at any position of 3t/4, t/2 or t/4 from the surface of the hot-dip plating layer, and Virtual grid lines are drawn on the cross section at 0.5 mm intervals, and the total area fraction A of [Zn phase] and [ternary eutectic structure of Al/MgZn2/Zn] is calculated in each of multiple regions partitioned by the virtual grid lines. The area where the ratio (B/A (%)) of the area fraction B of [Zn phase] is 20% or more is defined as the first area, and the area where the ratio (B/A (%)) is less than 20% is defined as the first area. This is the second area.
The components of the steel plate and the hot-dip coating layer of the hot-dip plated steel plate according to the second embodiment are the same as those of the hot-dip plated steel plate according to the first embodiment.
In the hot-dip galvanized steel sheet according to the second embodiment, the area ratio of the first region in the first portion is an area of 1.0 mm square or more, and the area ratio of the first region is an area of 1.0 mm square or more adjacent to the first portion. The absolute value of the difference between the portion and the area ratio of the first region is 30% or more. Here, "an area of 1.0 mm square or more" refers to an area larger than a 1.0 mm square. The area that can include the entire 1.0 mm square is "an area larger than or equal to 1.0 mm square." According to this characteristic point, the first portion and the second portion can be clearly identified with the naked eye. By forming the first portion and the second portion into arbitrary shapes, letters, designs, etc. can be displayed on the surface of the plating layer.
次に、本実施形態の溶融めっき鋼板の製造方法を説明する。
本実施形態の溶融めっき鋼板を溶融めっき法により製造するには、化学成分を調整した溶融めっき浴に鋼板を浸漬させることにより、溶融金属を鋼板表面に付着させる。次いで、鋼板をめっき浴から引き上げ、ガスワイピングにより付着量を制御した後に、溶融金属を凝固させる。凝固時には、組成にもよるが、最初に、〔Ａｌ相〕が形成され、その後、溶融金属の温度低下に伴い、〔Ａｌ／Ｚｎ／ＭｇＺｎ２の三元共晶組織〕が形成される。また、〔Ａｌ／Ｚｎ／ＭｇＺｎ２の三元共晶組織〕の素地中に、〔ＭｇＺｎ２相〕および〔Ｚｎ相〕が形成される。さらに、溶融めっき層中にＳｉが含有される場合は、〔Ａｌ／Ｚｎ／ＭｇＺｎ２の三元共晶組織〕の素地中に〔Ｍｇ２Ｓｉ相〕が形成される。 Next, a method for manufacturing a hot-dip plated steel sheet according to this embodiment will be explained.
In order to manufacture the hot-dip plated steel sheet of this embodiment by the hot-dip plating method, the steel sheet is immersed in a hot-dip plating bath whose chemical components have been adjusted, thereby causing molten metal to adhere to the surface of the steel sheet. Next, the steel plate is pulled out of the plating bath, and after controlling the amount of adhesion by gas wiping, the molten metal is solidified. During solidification, although it depends on the composition, [Al phase] is first formed, and then as the temperature of the molten metal decreases, [ternary eutectic structure of Al/Zn/MgZn 2 ] is formed. Moreover, [MgZn 2 phase] and [Zn phase] are formed in the matrix of [ternary eutectic structure of Al/Zn/MgZn 2 ]. Furthermore, when Si is contained in the hot-dip plating layer, a [Mg 2 Si phase] is formed in the matrix of [ternary eutectic structure of Al/Zn/MgZn 2 ].
本実施形態の溶融めっき鋼板を溶融めっき法により製造するには、化学成分を調整した溶融めっき浴に鋼板を浸漬させることにより、溶融金属を鋼板表面に付着させる。次いで、鋼板をめっき浴から引き上げ、ガスワイピングにより付着量を制御した後に、溶融金属を凝固させる。凝固時には、組成にもよるが、最初に、〔Ａｌ相〕が形成され、その後、溶融金属の温度低下に伴い、〔Ａｌ／Ｚｎ／ＭｇＺｎ２の三元共晶組織〕が形成される。また、〔Ａｌ／Ｚｎ／ＭｇＺｎ２の三元共晶組織〕の素地中に、〔ＭｇＺｎ２相〕および〔Ｚｎ相〕が形成される。さらに、溶融めっき層中にＳｉが含有される場合は、〔Ａｌ／Ｚｎ／ＭｇＺｎ２の三元共晶組織〕の素地中に〔Ｍｇ２Ｓｉ相〕が形成される。 Next, a method for manufacturing a hot-dip plated steel sheet according to this embodiment will be explained.
In order to manufacture the hot-dip plated steel sheet of this embodiment by the hot-dip plating method, the steel sheet is immersed in a hot-dip plating bath whose chemical components have been adjusted, thereby causing molten metal to adhere to the surface of the steel sheet. Next, the steel plate is pulled out of the plating bath, and after controlling the amount of adhesion by gas wiping, the molten metal is solidified. During solidification, although it depends on the composition, [Al phase] is first formed, and then as the temperature of the molten metal decreases, [ternary eutectic structure of Al/Zn/MgZn 2 ] is formed. Moreover, [MgZn 2 phase] and [Zn phase] are formed in the matrix of [ternary eutectic structure of Al/Zn/MgZn 2 ]. Furthermore, when Si is contained in the hot-dip plating layer, a [Mg 2 Si phase] is formed in the matrix of [ternary eutectic structure of Al/Zn/MgZn 2 ].
溶融めっきの凝固時に、粗大な〔Ｚｎ相〕が形成されると、溶融めっき層中の〔Ａｌ相〕や〔ＭｇＺｎ２相〕の比率が相対的に増加し、これらの相がめっき表面へ露出するため、溶融めっき層表面の外観が白色に近い外観を呈することを本発明者らが知見した。〔Ｚｎ相〕の形成は、Ｚｎの核生成点の数に影響を受けるものと推測される。すなわち、Ｚｎの核生成点が少ない場合、最終凝固直前における液相中のＺｎは〔Ａｌ／Ｚｎ／ＭｇＺｎ２の三元共晶組織〕中の微細なＺｎ相としては晶出されず、粗大な〔Ｚｎ〕相として晶出することを本発明者らが知見するに至った。Ｚｎの核生成点を少なくする手段としては、原板である鋼板の表面清浄度を高め、Ｚｎの核生成点となりうる物質を極力低減させることが考えられる。
When a coarse [Zn phase] is formed during solidification of hot-dip plating, the ratio of [Al phase] and [MgZn 2 phase] in the hot-dip plating layer increases relatively, and these phases are exposed to the plating surface. The present inventors have found that, as a result, the surface of the hot-dip plating layer has a nearly white appearance. It is presumed that the formation of [Zn phase] is influenced by the number of Zn nucleation points. In other words, when there are few Zn nucleation points, Zn in the liquid phase just before final solidification is not crystallized as a fine Zn phase in [ternary eutectic structure of Al/Zn/MgZn2 ] , but as a coarse Zn phase. The present inventors have come to the knowledge that it crystallizes as a [Zn] phase. As a means to reduce the number of Zn nucleation points, it is possible to improve the surface cleanliness of the steel sheet that is the original sheet and to reduce as much as possible substances that can become Zn nucleation points.
一方、Ｚｎの核生成点が多い場合では、最終凝固直前における液相中のＺｎは、〔Ａｌ／Ｚｎ／ＭｇＺｎ２の三元共晶組織〕中の微細なＺｎ相として晶出し、粗大な〔Ｚｎ〕相としては晶出しにくくなり、溶融めっき層表面の外観が金属光沢の外観を呈するようになる。Ｚｎの核生成点を多くする手段としては、鋼板の表面清浄度を高めた後に、Ｚｎの核生成点となりうる物質を所定のパターンになるように配置することが考えられる。
On the other hand, when there are many Zn nucleation points, Zn in the liquid phase immediately before final solidification crystallizes as a fine Zn phase in the [ternary eutectic structure of Al/Zn/MgZn2 ] , and forms a coarse [ The Zn] phase is difficult to crystallize, and the surface of the hot-dip plating layer takes on a metallic luster appearance. A conceivable way to increase the number of Zn nucleation points is to increase the surface cleanliness of the steel plate and then arrange substances that can become Zn nucleation points in a predetermined pattern.
以下、本実施形態の溶融めっき鋼板の製造方法をより詳細に説明する。本実施形態の溶融めっき鋼板は、鋼板表面の清浄度を高める処理を行い、次いで、清浄度が低い領域を所定のパターンになるように配置する。次いで鋼板を溶融めっき浴に浸漬させてから引き上げ、次いで冷却して溶融めっき層を凝固させることによって製造する。
Hereinafter, the method for manufacturing the hot-dip plated steel sheet of this embodiment will be explained in more detail. The hot-dip plated steel sheet of this embodiment is treated to increase the cleanliness of the surface of the steel sheet, and then regions with low cleanliness are arranged in a predetermined pattern. Next, the steel plate is immersed in a hot-dip plating bath, pulled out, and then cooled to solidify the hot-dip plating layer.
具体的には、まず、熱間圧延鋼板を製造し、必要に応じて熱延板焼鈍を行う。酸洗後、冷間圧延を行い、冷延板とする。冷延板を脱脂、水洗した後、焼鈍（冷延板焼鈍）し、焼鈍後の冷延板を溶融めっき浴に浸漬させて溶融めっき層を形成する。ここで、冷間圧延から冷延板焼鈍する間において、表面清浄度を高めるために、鋼板に対してアルカリ電解洗浄を行い、純水で水洗後、不活性雰囲気の下で乾燥してから、冷延板焼鈍工程へと移行する。冷延板焼鈍は、アルカリ電解洗浄の終了時から１０秒以内に実施する。アルカリ電解洗浄の終了時は、アルカリ電解洗浄の最後の純水によるスプレー水洗の抽出時とする。焼鈍条件は特に限定はない。
Specifically, first, a hot-rolled steel plate is manufactured, and if necessary, the hot-rolled plate is annealed. After pickling, cold rolling is performed to obtain a cold rolled sheet. After the cold-rolled sheet is degreased and washed with water, it is annealed (cold-rolled sheet annealing), and the annealed cold-rolled sheet is immersed in a hot-dip plating bath to form a hot-dip plating layer. Here, in order to increase the surface cleanliness between cold rolling and cold rolled sheet annealing, the steel sheet is subjected to alkaline electrolytic cleaning, washed with pure water, and then dried under an inert atmosphere. Move on to the cold rolled plate annealing process. Cold-rolled sheet annealing is performed within 10 seconds from the end of alkaline electrolytic cleaning. The end of alkaline electrolytic cleaning is the time of extraction of spray water washing with pure water at the end of alkaline electrolytic cleaning. There are no particular limitations on the annealing conditions.
アルカリ電解洗浄に用いる洗浄液としては、例えば水酸化ナトリウムまたは水酸化カリウムを含むアルカリ性の洗浄液が好ましい。アルカリ電解洗浄の手順としては、洗浄液中に鋼板を浸漬して浸漬洗浄した後、洗浄液中にて鋼板を電解洗浄する。電解洗浄は、交番電解洗浄が好ましい。次いで、純水を鋼板表面にスプレーすることで、付着した洗浄液を洗い流す。スプレー水洗は、鋼板の進行方向に沿って複数基のスプレーノズルを配置し、各ノズルから純水を噴射させてもよい。純水としては、電気抵抗率が１ＭΩ・ｃｍ以上の水がよい。
As the cleaning liquid used for alkaline electrolytic cleaning, an alkaline cleaning liquid containing, for example, sodium hydroxide or potassium hydroxide is preferable. As a procedure for alkaline electrolytic cleaning, a steel plate is immersed in a cleaning liquid, and then the steel plate is electrolytically cleaned in the cleaning liquid. The electrolytic cleaning is preferably alternating electrolytic cleaning. Next, the adhering cleaning liquid is washed away by spraying pure water onto the surface of the steel plate. Spray washing may be performed by arranging a plurality of spray nozzles along the traveling direction of the steel plate and spraying pure water from each nozzle. As pure water, water with an electrical resistivity of 1 MΩ·cm or more is preferable.
スプレー水洗の抽出後から焼鈍を行うまでの間、不活性雰囲気中にて乾燥を行うことによって鋼板表面に付着した水分を極力除去することが、空気中の微細な浮遊粒子の付着を抑制できる点で好ましい。
Drying in an inert atmosphere after extraction in spray water washing until annealing to remove as much moisture as possible from the surface of the steel sheet can suppress the adhesion of fine suspended particles in the air. It is preferable.
アルカリ電解洗浄によって鋼板表面に付着した有機系の汚れを除去し、更に純水による最終のスプレー水洗終了後から焼鈍までの間を不活性雰囲気中で乾燥し、その後に焼鈍を行うことで、空気中の微細な浮遊粒子が冷延板上に固着することを防止することができる。
Organic stains adhering to the surface of the steel plate are removed by alkaline electrolytic cleaning, and then drying is performed in an inert atmosphere after the final spray cleaning with pure water until annealing, and then annealing is performed. It is possible to prevent fine floating particles inside from sticking to the cold-rolled plate.
次いで、冷延板焼鈍から溶融めっきに浸漬させるまでの間において、Ｚｎの核生成点を増加させるべく、焼鈍後の冷延板にＺｎ粉を所定形状となるように付着させる。焼鈍後の冷延板へのＺｎ粉の付着は、予めロールに所定形状となるようにＺｎ粉を付着させておき、当該ロールを焼鈍後の冷延板が通過する際に転写させる方法としてもよい。
Next, during the period from annealing the cold-rolled sheet to immersion in hot-dip plating, Zn powder is attached to the annealed cold-rolled sheet in a predetermined shape in order to increase the number of Zn nucleation points. Zn powder can be attached to the cold-rolled sheet after annealing by attaching the Zn powder to a roll in advance in a predetermined shape, and transferring the Zn powder when the cold-rolled sheet after annealing passes through the roll. good.
付着させたＺｎ粉は溶融めっき中には完全溶解せず、めっきの最終凝固時にＺｎの核生成サイトとなる。一部のＺｎ粉は固体のままめっき浴中に拡散する。冷延焼鈍前にＺｎ粉を付着させると、焼鈍時にＺｎが鋼板と合金化してしまい、溶融めっき層の形成が阻害されるので好ましくない。また、溶融めっき浴への浸漬後にＺｎ粉を付着させた場合、付着したＺｎ粉によってかえってめっきの表面外観が荒れる原因となる。付着させるＺｎ粉は、Ｚｎおよび不純物を含有するＺｎ粉であればよい。Ｚｎ粉の平均粒径は例えば４～６μｍの範囲であればよい。Ｚｎ粉の付着量は、例えば、１～５ｇ／ｍ２程度がよい。平均粒径および付着量がこの範囲であれば、Ｚｎ粉をＺｎの核生成サイトとして機能させることができる。
The attached Zn powder does not completely dissolve during hot-dip plating, and becomes a Zn nucleation site during final solidification of the plating. Some Zn powder is diffused into the plating bath as a solid. If Zn powder is attached before cold rolling annealing, Zn will alloy with the steel sheet during annealing, which will inhibit the formation of a hot-dip plating layer, which is not preferable. Moreover, if Zn powder is attached after immersion in a hot-dip plating bath, the attached Zn powder will cause the surface appearance of the plating to become rough. The Zn powder to be deposited may be any Zn powder containing Zn and impurities. The average particle size of the Zn powder may be, for example, in the range of 4 to 6 μm. The amount of Zn powder deposited is preferably about 1 to 5 g/m 2 , for example. If the average particle size and the amount of adhesion are within this range, the Zn powder can function as a Zn nucleation site.
次に、鋼板を、溶融めっき浴に浸漬させる。溶融めっき浴は、Ａｌ：５～２２質量％、Ｍｇ：１．０～１０質量％を含有し、残部としてＺｎおよび不純物を含む。更に、溶融めっき浴は、Ｓｉ：０．０００１～２質量％を含有してもよい。更にまた、溶融めっき浴は、Ｎｉ、Ｔｉ、Ｚｒ、Ｓｒ、Ｆｅ、Ｓｂ、Ｐｂ、Ｓｎ、Ｃａ、Ｃｏ、Ｍｎ、Ｐ、Ｂ、Ｂｉ、Ｃｒ、Ｓｃ、Ｙ、ＲＥＭ、Ｈｆ、Ｃのいずれか１種または２種以上を、合計で０．０００１～２質量％含有してもよい。
溶融めっき法は、鋼板を溶融めっき浴に連続通板させる連続式溶融めっき法とする。 Next, the steel plate is immersed in a hot-dip plating bath. The hot-dip plating bath contains Al: 5 to 22% by mass, Mg: 1.0 to 10% by mass, and the balance contains Zn and impurities. Furthermore, the hot-dip plating bath may contain Si: 0.0001 to 2% by mass. Furthermore, the hot-dip plating bath includes any one of Ni, Ti, Zr, Sr, Fe, Sb, Pb, Sn, Ca, Co, Mn, P, B, Bi, Cr, Sc, Y, REM, Hf, and C. One or more types may be contained in a total amount of 0.0001 to 2% by mass.
The hot-dip plating method is a continuous hot-dip plating method in which the steel plate is continuously passed through a hot-dip plating bath.
溶融めっき法は、鋼板を溶融めっき浴に連続通板させる連続式溶融めっき法とする。 Next, the steel plate is immersed in a hot-dip plating bath. The hot-dip plating bath contains Al: 5 to 22% by mass, Mg: 1.0 to 10% by mass, and the balance contains Zn and impurities. Furthermore, the hot-dip plating bath may contain Si: 0.0001 to 2% by mass. Furthermore, the hot-dip plating bath includes any one of Ni, Ti, Zr, Sr, Fe, Sb, Pb, Sn, Ca, Co, Mn, P, B, Bi, Cr, Sc, Y, REM, Hf, and C. One or more types may be contained in a total amount of 0.0001 to 2% by mass.
The hot-dip plating method is a continuous hot-dip plating method in which the steel plate is continuously passed through a hot-dip plating bath.
溶融めっき浴の温度は、組成によって異なるが、例えば、４００～５００℃の範囲が好ましい。溶融めっき浴の温度がこの範囲であれば、所望の溶融めっき層を形成できるためである。
また、溶融めっき層の付着量は、溶融めっき浴から引き上げられた鋼板に対してガスワイピング等の手段で調整すればよい。溶融めっき層の付着量は、鋼板両面の合計の付着量が３０～６００ｇ／ｍ２の範囲になるように調整することが好ましい。付着量が３０ｇ／ｍ２未満の場合、溶融めっき鋼板の耐食性が低下するので好ましくない。付着量が６００ｇ／ｍ２超の場合、鋼板に付着した溶融金属の垂れが発生して、溶融めっき層の表面を平滑にすることができなくなるため好ましくない。 The temperature of the hot-dip plating bath varies depending on the composition, but is preferably in the range of 400 to 500°C, for example. This is because if the temperature of the hot-dip plating bath is within this range, a desired hot-dip plating layer can be formed.
Further, the amount of the hot-dip coating layer to be deposited may be adjusted by means such as gas wiping on the steel sheet pulled out of the hot-dip coating bath. The amount of hot-dip plating layer deposited is preferably adjusted so that the total amount of deposit on both sides of the steel plate is in the range of 30 to 600 g/m 2 . If the adhesion amount is less than 30 g/m 2 , the corrosion resistance of the hot-dip plated steel sheet decreases, which is not preferable. If the amount of adhesion exceeds 600 g/m 2 , the molten metal adhering to the steel plate will sag, making it impossible to make the surface of the hot-dip plating layer smooth, which is not preferable.
また、溶融めっき層の付着量は、溶融めっき浴から引き上げられた鋼板に対してガスワイピング等の手段で調整すればよい。溶融めっき層の付着量は、鋼板両面の合計の付着量が３０～６００ｇ／ｍ２の範囲になるように調整することが好ましい。付着量が３０ｇ／ｍ２未満の場合、溶融めっき鋼板の耐食性が低下するので好ましくない。付着量が６００ｇ／ｍ２超の場合、鋼板に付着した溶融金属の垂れが発生して、溶融めっき層の表面を平滑にすることができなくなるため好ましくない。 The temperature of the hot-dip plating bath varies depending on the composition, but is preferably in the range of 400 to 500°C, for example. This is because if the temperature of the hot-dip plating bath is within this range, a desired hot-dip plating layer can be formed.
Further, the amount of the hot-dip coating layer to be deposited may be adjusted by means such as gas wiping on the steel sheet pulled out of the hot-dip coating bath. The amount of hot-dip plating layer deposited is preferably adjusted so that the total amount of deposit on both sides of the steel plate is in the range of 30 to 600 g/m 2 . If the adhesion amount is less than 30 g/m 2 , the corrosion resistance of the hot-dip plated steel sheet decreases, which is not preferable. If the amount of adhesion exceeds 600 g/m 2 , the molten metal adhering to the steel plate will sag, making it impossible to make the surface of the hot-dip plating layer smooth, which is not preferable.
溶融めっき層の付着量を調整した後、鋼板を冷却する。冷却条件は特に限定する必要はない。鋼板に付着した溶融金属の冷却は、溶融めっき浴から鋼板を引き上げた後に開始される。溶融めっき浴の組成にもよるが、たとえば、４３０℃付近から〔Ａｌ相〕が晶出し始める。次いで、３７０℃付近から〔ＭｇＺｎ２相〕が晶出し始め、３４０℃付近から〔Ａｌ／Ｚｎ／ＭｇＺｎ２の三元共晶組織〕が晶出し、更に〔Ｚｎ相〕が晶出して、凝固が完了する。
After adjusting the adhesion amount of the hot-dip plating layer, the steel plate is cooled. Cooling conditions do not need to be particularly limited. Cooling of the molten metal adhering to the steel plate is started after the steel plate is pulled up from the hot-dip plating bath. Although it depends on the composition of the hot-dip plating bath, for example, [Al phase] starts to crystallize around 430°C. Next, [MgZn 2 phase] starts to crystallize from around 370°C, [ternary eutectic structure of Al/Zn/MgZn 2] starts to crystallize from around 340°C, and further [Zn phase] crystallizes, and solidification stops. Complete.
溶融めっき前の鋼板表面は、全面にわたって清浄度が高められた後に、Ｚｎの核生成点となるＺｎ粉付着領域が配置される。Ｚｎ粉付着領域には、Ｚｎの核生成点が多く含まれるため、共晶組織としてのＺｎまたはＭｇＺｎ２が晶出されて〔Ａｌ／Ｚｎ／ＭｇＺｎ２の三元共晶組織〕が多く形成され、他方、液相中のＺｎが減少して、粗大な〔Ｚｎ相〕の形成が抑制される。これにより、Ｚｎ粉付着領域では、〔Ｚｎ相〕および〔Ａｌ／ＭｇＺｎ２／Ｚｎの三元共晶組織〕の合計面積分率Ａに対する〔Ｚｎ相〕の面積分率Ｂの比率（Ｂ／Ａ（％））が低くなる。一方、Ｚｎ粉が付着されず清浄度が比較的高いままの領域では、比率（Ｂ／Ａ（％））が高くなる。
After the surface of the steel sheet before hot-dip plating has been made clean over the entire surface, a Zn powder adhesion region that serves as a nucleation point for Zn is arranged. Since the Zn powder adhesion region contains many Zn nucleation points, Zn or MgZn 2 as a eutectic structure is crystallized and a large amount of [ternary eutectic structure of Al/Zn/MgZn 2 ] is formed. On the other hand, Zn in the liquid phase is reduced, and the formation of a coarse [Zn phase] is suppressed. As a result, in the Zn powder adhesion region, the ratio of the area fraction B of [Zn phase] to the total area fraction A of [Zn phase] and [ternary eutectic structure of Al/MgZn 2 /Zn] (B/A (%)) becomes lower. On the other hand, the ratio (B/A (%)) becomes high in areas where Zn powder is not attached and the cleanliness remains relatively high.
本実施形態の溶融めっき鋼板は、第１領域及び第２領域のうち、パターン部における第１領域の面積率と、非パターン部における第１領域の面積率との差の絶対値を３０％以上とすることで、パターン部と非パターン部とを識別できるようになる。形成されたパターン部及び非パターン部は、印刷や塗装によって形成されたものではないため、耐久性が高くなっている。また、パターン部及び非パターン部が印刷や塗装によって形成されたものではないため、溶融めっき層の耐食性への影響もない。更に、パターン部及び非パターン部は、溶融めっき層の表面を研削等によって形成したものではない。従って、パターン部における溶融めっき層の厚みは、非パターン部における溶融めっき層の厚みに比べて、耐食性が劣化するほどのめっき層の厚みの減少はみられない。よって、本実施形態の溶融めっき鋼板は、耐食性に優れたものとなる。
In the hot-dip galvanized steel sheet of this embodiment, the absolute value of the difference between the area ratio of the first region in the pattern part and the area ratio of the first region in the non-pattern part among the first region and the second region is 30% or more. By doing so, it becomes possible to distinguish between pattern portions and non-pattern portions. The formed pattern parts and non-pattern parts have high durability because they are not formed by printing or painting. Further, since the patterned portion and the non-patterned portion are not formed by printing or painting, there is no influence on the corrosion resistance of the hot-dip plating layer. Further, the patterned portion and the non-patterned portion are not formed by grinding or the like on the surface of the hot-dip plating layer. Therefore, the thickness of the hot-dip plated layer in the patterned area does not decrease to the extent that the corrosion resistance deteriorates compared to the thickness of the hot-dipped plated layer in the non-patterned area. Therefore, the hot-dip plated steel sheet of this embodiment has excellent corrosion resistance.
本実施形態によれば、パターン部の耐久性が高く、耐食性等の好適なめっき特性を有する溶融めっき鋼板を提供できる。特に本実施形態では、清浄度を高めた焼鈍後の冷延板に対して所定の形状とした範囲にＺｎ粉を付着させたロールを押し付けて、ロールの表面形状を焼鈍後の冷延板に転写することで、溶融めっき後に、溶融めっき層の表面をパターン部または非パターン部の範囲を意図的若しくは人工的な形状にすることができ、直線部、曲線部、ドット部、図形、数字、記号若しくは文字のいずれか１種またはこれらのうちの２種以上を組合せた形状となるようにパターン部を配置できる。これにより、溶融めっき層の表面に、印刷、塗装または研削を行うことなく様々な意匠、商標、その他の識別マークを表すことができ、鋼板の出所の識別性やデザイン性等を高めることができる。また、パターン部によって、工程管理や在庫管理などに必要な情報や需要者が求める任意の情報を、溶融めっき鋼板に付与することもできる。
これにより、溶融めっき鋼板の生産性の向上にも寄与することができる。 According to this embodiment, it is possible to provide a hot-dip plated steel sheet that has high durability in the pattern portion and has suitable plating properties such as corrosion resistance. In particular, in this embodiment, a roll with Zn powder adhered to a predetermined shape area is pressed against an annealed cold-rolled sheet with increased cleanliness, and the surface shape of the roll is changed to the annealed cold-rolled sheet. By transferring, after hot-dip plating, the surface of the hot-dip plating layer can be made into an intentional or artificial shape in the patterned area or non-patterned area, including straight parts, curved parts, dotted parts, figures, numbers, etc. The pattern portion can be arranged to have a shape that is either one of symbols or characters, or a combination of two or more of these. As a result, various designs, trademarks, and other identification marks can be displayed on the surface of the hot-dip coating layer without printing, painting, or grinding, and it is possible to improve the identifiability of the origin of the steel plate and the design quality. . Further, the pattern portion can provide the hot-dip plated steel sheet with information necessary for process management, inventory management, etc., or any information desired by the consumer.
This can also contribute to improving the productivity of hot-dip galvanized steel sheets.
これにより、溶融めっき鋼板の生産性の向上にも寄与することができる。 According to this embodiment, it is possible to provide a hot-dip plated steel sheet that has high durability in the pattern portion and has suitable plating properties such as corrosion resistance. In particular, in this embodiment, a roll with Zn powder adhered to a predetermined shape area is pressed against an annealed cold-rolled sheet with increased cleanliness, and the surface shape of the roll is changed to the annealed cold-rolled sheet. By transferring, after hot-dip plating, the surface of the hot-dip plating layer can be made into an intentional or artificial shape in the patterned area or non-patterned area, including straight parts, curved parts, dotted parts, figures, numbers, etc. The pattern portion can be arranged to have a shape that is either one of symbols or characters, or a combination of two or more of these. As a result, various designs, trademarks, and other identification marks can be displayed on the surface of the hot-dip coating layer without printing, painting, or grinding, and it is possible to improve the identifiability of the origin of the steel plate and the design quality. . Further, the pattern portion can provide the hot-dip plated steel sheet with information necessary for process management, inventory management, etc., or any information desired by the consumer.
This can also contribute to improving the productivity of hot-dip galvanized steel sheets.
次に、本発明の実施例を説明する。冷間圧延後の鋼板をアルカリ電解洗浄を行い、超純水で洗浄した後、不活性雰囲気下で１０秒以内に焼鈍工程へと移行した。アルカリ電解洗浄に用いる洗浄液としては、水酸化ナトリウムを含むアルカリ性の洗浄液とした。アルカリ電解洗浄の手順としては、洗浄液中に鋼板を浸漬して浸漬洗浄した後、洗浄液中にて鋼板を電解洗浄した。電解洗浄は、交番電解洗浄とした。次いで、超純水にてスプレー水洗することで、付着した洗浄液を洗い流した。超純水としては、電気抵抗率が１ＭΩ・ｃｍ以上の水とした。その後、不活性雰囲気中にて乾燥してから、冷延板焼鈍を行った。焼鈍条件は、均熱温度８００℃、均熱時間は１分とした。
Next, examples of the present invention will be described. After the steel plate after cold rolling was subjected to alkaline electrolytic cleaning and washed with ultrapure water, it was transferred to an annealing process within 10 seconds in an inert atmosphere. The cleaning liquid used in the alkaline electrolytic cleaning was an alkaline cleaning liquid containing sodium hydroxide. As a procedure for alkaline electrolytic cleaning, the steel plate was immersed in a cleaning solution for immersion cleaning, and then the steel plate was electrolytically cleaned in the cleaning solution. The electrolytic cleaning was an alternating electrolytic cleaning. Next, the attached cleaning liquid was washed away by spray washing with ultrapure water. The ultrapure water was water with an electrical resistivity of 1 MΩ·cm or more. Then, after drying in an inert atmosphere, cold-rolled sheet annealing was performed. The annealing conditions were a soaking temperature of 800° C. and a soaking time of 1 minute.
焼鈍後、図４に示されるような格子状パターンが転写された形状をもつ金属板に、平均粒径４～６μｍの範囲のＺｎ粉を付着させた。格子状パターンを構成する線の太さは１０ｍｍとした。線の中心軸の間隔は５０ｍｍとした。そして、この金属板を焼鈍後の鋼板に押し付けて鋼板表面にＺｎ粉を転写することにより、Ｚｎの核生成サイトを局所的（５０ｍｍ間隔の格子状）に形成した。Ｚｎ粉の付着量は１～５ｇ／ｍ２の範囲とした。その後、鋼板を溶融めっき浴に浸漬してから引き上げた。その後、付着量をガスワイピングによって調整し、さらに冷却を行った。このようにして、表１Ａ～表３Ｂに示すＮｏ．１～Ｎｏ．５１の溶融めっき鋼板を製造した。
After annealing, Zn powder having an average particle size in the range of 4 to 6 μm was attached to a metal plate having a shape onto which a lattice pattern as shown in FIG. 4 was transferred. The thickness of the lines constituting the grid pattern was 10 mm. The distance between the central axes of the lines was 50 mm. Then, by pressing this metal plate against the annealed steel plate and transferring Zn powder to the surface of the steel plate, Zn nucleation sites were formed locally (in a lattice shape with intervals of 50 mm). The amount of Zn powder deposited was in the range of 1 to 5 g/m 2 . Thereafter, the steel plate was immersed in a hot-dip plating bath and then pulled out. Thereafter, the amount of adhesion was adjusted by gas wiping, and further cooling was performed. In this way, No. 1 shown in Tables 1A to 3B. 1~No. 51 hot-dip galvanized steel sheets were manufactured.
ただし、一部の鋼板には、Ｚｎ粉を付着させなかった。Ｚｎ粉を付着させなかった鋼板に対して、Ｎｏ．１～４８と同様の条件で溶融めっき浴によるめっき処理をして、溶融めっき鋼板を製造した。この鋼板の溶融めっき層の表面に、インクジェット法により、５０ｍｍ間隔の格子状パターンを印刷した。このようにして、Ｎｏ．５２のＺｎ－Ａｌ－Ｍｇ系溶融めっき鋼板を製造した。
However, Zn powder was not attached to some of the steel plates. For the steel plate to which no Zn powder was attached, No. A hot-dip plated steel sheet was produced by performing plating treatment using a hot-dip plating bath under the same conditions as Nos. 1 to 48. A lattice pattern with 50 mm intervals was printed on the surface of the hot-dip plating layer of this steel plate by an inkjet method. In this way, No. No. 52 Zn-Al-Mg hot-dip plated steel sheets were manufactured.
また、Ｚｎ粉を付着させなかった鋼板に対して、Ｎｏ．１～４８と同様の条件で溶融めっき浴によるめっき処理をして、溶融めっき鋼板を製造した。その後、溶融めっき層の表面を研削して、５０ｍｍ間隔の格子状パターンを形成した。このようにして、Ｎｏ．５３の溶融めっき鋼板を製造した。
In addition, for the steel plate to which Zn powder was not attached, No. A hot-dip plated steel sheet was produced by performing plating treatment using a hot-dip plating bath under the same conditions as Nos. 1 to 48. Thereafter, the surface of the hot-dip plating layer was ground to form a lattice pattern with intervals of 50 mm. In this way, No. 53 hot-dip galvanized steel sheets were manufactured.
得られた溶融めっき鋼板について、パターン部及び非パターン部に含まれる第１領域、第２領域の面積率を求めた。まず、パターン部及び非パターン部の境界は、溶融めっき層の表面を肉眼で観察することにより特定した。肉眼での境界の特定が難しい場合は、拡大鏡や光学顕微鏡の拡大像を利用した。境界の判別が難しい例では、ロール表面の正方形パターンに対応する箇所がパターン部であるとして第１領域、第２領域の面積率を評価した。
Regarding the obtained hot-dip plated steel sheet, the area ratios of the first region and the second region included in the patterned portion and the non-patterned portion were determined. First, the boundary between the patterned portion and the non-patterned portion was identified by visually observing the surface of the hot-dip plating layer. If it was difficult to identify the boundaries with the naked eye, magnified images from a magnifying glass or optical microscope were used. In an example where it was difficult to determine the boundary, the area ratios of the first region and the second region were evaluated assuming that the portion corresponding to the square pattern on the roll surface was the pattern portion.
次に、パターン部及び非パターン部に含まれる各領域の面積率は、次に説明する測定方法により求めた。まず、鋼板上に形成された溶融めっき層の厚みをｔとし、溶融めっき層の表面からｔ／２位置において表面に平行な５ｍｍ四方の露出面を形成した。ただし、ｔ／２が０．２μｍを超える場合、表面から０．２μｍ位置において、露出面を形成した。この際、パターン部の内部に完全に包含される５ｍｍ四方の露出面（即ち、全域がパターン部に該当する露出面）、及び非パターン部の内部に完全に包含される５ｍｍ四方の露出面（即ち、全域が非パターン部に該当する露出面）を形成した。この露出面を形成する際には、研削により、溶融めっき層を削り取った。また、露出面の最大高さＲｚを０．２μｍ以下とした。
Next, the area ratio of each region included in the pattern portion and the non-pattern portion was determined by the measurement method described below. First, the thickness of the hot-dip plating layer formed on the steel plate was t, and a 5 mm square exposed surface parallel to the surface was formed at a position t/2 from the surface of the hot-dip plating layer. However, when t/2 exceeded 0.2 μm, an exposed surface was formed at a position of 0.2 μm from the surface. At this time, a 5 mm square exposed surface that is completely included inside the pattern section (that is, an exposed surface whose entire area corresponds to the pattern section), and a 5 mm square exposed surface that is completely included inside the non-pattern section ( That is, the entire exposed surface corresponds to a non-patterned portion). When forming this exposed surface, the hot-dip plating layer was removed by grinding. Further, the maximum height Rz of the exposed surface was set to 0.2 μm or less.
次いで、観察対象とする露出面に、まず、溶融めっき層の表面に０．５ｍｍ間隔で仮想格子線を描き、仮想格子線によって区画される複数の領域（０．５ｍｍ四方）においてそれぞれ、比率（Ｂ／Ａ（％））を測定した。
Next, on the exposed surface to be observed, virtual grid lines are first drawn at 0.5 mm intervals on the surface of the hot-dip plating layer, and the ratio ( B/A (%)) was measured.
比率（Ｂ／Ａ（％））の測定は、次のようにして行った。走査型電子顕微鏡（ＳＥＭ）の二次電子像により、領域毎にめっき組織を観察して、〔Ｚｎ相〕および〔Ａｌ／ＭｇＺｎ２／Ｚｎの三元共晶組織〕を特定した。各相および組織を特定する際は、ＳＥＭに付属するエネルギー分散型Ｘ線元素分析装置による元素分析を併用し、Ｚｎ、ＡｌおよびＭｇの分布を確認しつつ特定した。すなわち、Ｚｎ、ＡｌおよびＭｇのうち、Ｚｎが主として検出される領域をＺｎ相とし、Ａｌが主として検出される領域をＡｌ相とし、ＺｎとＭｇが主として検出される領域をＭｇＺｎ２相とした。検出された各相の分布から、上述の方法に従って、〔Ａｌ相〕、〔ＭｇＺｎ２相〕および〔Ｚｎ相〕と、〔Ａｌ／Ｚｎ／ＭｇＺｎ２の三元共晶組織〕に分類した。そして、〔Ｚｎ相〕および〔Ａｌ／ＭｇＺｎ２／Ｚｎの三元共晶組織〕の合計面積分率Ａに対する〔Ｚｎ相〕の面積分率Ｂの比率（Ｂ／Ａ（％））を、仮想格子線によって区画される複数の領域（０．５ｍｍ四方）それぞれにおいて求める。〔Ｚｎ相〕は、円相当直径で２．５μｍ以上となる領域のものを〔Ｚｎ相〕として計測した。これにより、〔Ａｌ／ＭｇＺｎ２／Ｚｎの三元共晶組織〕中のＺｎ相と〔Ｚｎ相〕とを区別した。
The ratio (B/A (%)) was measured as follows. The plating structure was observed for each region using a secondary electron image using a scanning electron microscope (SEM), and [Zn phase] and [ternary eutectic structure of Al/MgZn 2 /Zn] were identified. When specifying each phase and structure, elemental analysis using an energy dispersive X-ray elemental analyzer attached to the SEM was also used, and the distribution of Zn, Al, and Mg was confirmed. That is, among Zn, Al, and Mg, the region where Zn is mainly detected is defined as the Zn phase, the region where Al is mainly detected is defined as the Al phase, and the region where Zn and Mg are mainly detected is defined as the MgZn 2 phase. Based on the distribution of each detected phase, it was classified into [Al phase], [MgZn 2 phase], [Zn phase], and [ternary eutectic structure of Al/Zn/MgZn 2 ] according to the method described above. Then, the ratio (B/A (%)) of the area fraction B of [Zn phase] to the total area fraction A of [Zn phase] and [ternary eutectic structure of Al/MgZn 2 /Zn] is calculated as follows: It is determined in each of a plurality of areas (0.5 mm square) divided by grid lines. [Zn phase] was measured as a region having a circular equivalent diameter of 2.5 μm or more as [Zn phase]. Thereby, the Zn phase in the [ternary eutectic structure of Al/MgZn 2 /Zn] was distinguished from the [Zn phase].
比率（Ｂ／Ａ（％））が２０％以上の領域を第１領域とし、比率（Ｂ／Ａ（％））が２０％未満の領域を第２領域とした。
The region where the ratio (B/A (%)) was 20% or more was defined as the first region, and the region where the ratio (B/A (%)) was less than 20% was defined as the second region.
そして、パターン部における第１領域の面積率及び非パターン部における第１領域の面積率を求めた。また、パターン部における第１領域の面積率と、非パターン部における第１領域の面積率との差を求めた。
Then, the area ratio of the first region in the pattern part and the area ratio of the first region in the non-pattern part were determined. Furthermore, the difference between the area ratio of the first region in the pattern portion and the area ratio of the first region in the non-pattern portion was determined.
［識別性］
正方形状のパターン部を施した試験板の、製造した直後の初期状態のものと、６ヶ月間屋外暴露した経時状態のものを対象に、下記の判定基準に基づいて目視評価した。初期状態、経時状態とも、Ａ、Ｂ及びＣを合格とした。 [Identifiability]
Visual evaluation was performed based on the following criteria for test plates with square pattern sections, both in the initial state immediately after manufacture and in the aged state after being exposed outdoors for 6 months. In both the initial state and the aged state, A, B, and C were passed.
正方形状のパターン部を施した試験板の、製造した直後の初期状態のものと、６ヶ月間屋外暴露した経時状態のものを対象に、下記の判定基準に基づいて目視評価した。初期状態、経時状態とも、Ａ、Ｂ及びＣを合格とした。 [Identifiability]
Visual evaluation was performed based on the following criteria for test plates with square pattern sections, both in the initial state immediately after manufacture and in the aged state after being exposed outdoors for 6 months. In both the initial state and the aged state, A, B, and C were passed.
Ａ：５ｍ先からでもパターン部を視認できる。
Ｂ：５ｍ先からはパターン部を視認できないが、３ｍ先からの視認性は高い。
Ｃ：３ｍ先からはパターン部を視認できないが、１ｍ先からの視認性は高い。
Ｄ：１ｍ先からパターン部を視認できない。 A: The pattern part can be seen even from 5m away.
B: The pattern part cannot be seen from 5 m away, but visibility is high from 3 m away.
C: The pattern part cannot be seen from 3 m away, but visibility is high from 1 m away.
D: The pattern part cannot be seen from 1 m away.
Ｂ：５ｍ先からはパターン部を視認できないが、３ｍ先からの視認性は高い。
Ｃ：３ｍ先からはパターン部を視認できないが、１ｍ先からの視認性は高い。
Ｄ：１ｍ先からパターン部を視認できない。 A: The pattern part can be seen even from 5m away.
B: The pattern part cannot be seen from 5 m away, but visibility is high from 3 m away.
C: The pattern part cannot be seen from 3 m away, but visibility is high from 1 m away.
D: The pattern part cannot be seen from 1 m away.
［耐食性］
試験板を１５０×７０ｍｍに切断し、ＪＡＳＯ－Ｍ６０９に準拠した腐食促進試験ＣＣＴを３０サイクル試験した後、錆発生状況を調査し、下記の判定基準に基づいて評価した。Ａ、Ｂ、及びＣを合格とした。
Ａ：錆発生がなく、パターン部と非パターン部ともに美麗な意匠外観を維持している。
Ｂ：錆発生はないが、パターン部と非パターン部にごくわずかな意匠外観変化が認められる。
Ｃ：意匠外観がやや損なわれているが、パターン部と非パターン部が目視で区別できる。
Ｄ：パターン部と非パターン部の外観品位が著しく低下しており、目視で区別できない。 [Corrosion resistance]
The test plate was cut into 150 x 70 mm and subjected to 30 cycles of accelerated corrosion test CCT in accordance with JASO-M609, and then the rust occurrence was investigated and evaluated based on the following criteria. A, B, and C were passed.
A: No rust occurs, and both patterned and non-patterned parts maintain a beautiful design appearance.
B: No rust occurred, but a very slight change in the design appearance was observed between the patterned part and the non-patterned part.
C: The design appearance is slightly impaired, but the patterned area and the non-patterned area can be visually distinguished.
D: The appearance quality of the patterned portion and the non-patterned portion is significantly degraded and cannot be visually distinguished.
試験板を１５０×７０ｍｍに切断し、ＪＡＳＯ－Ｍ６０９に準拠した腐食促進試験ＣＣＴを３０サイクル試験した後、錆発生状況を調査し、下記の判定基準に基づいて評価した。Ａ、Ｂ、及びＣを合格とした。
Ａ：錆発生がなく、パターン部と非パターン部ともに美麗な意匠外観を維持している。
Ｂ：錆発生はないが、パターン部と非パターン部にごくわずかな意匠外観変化が認められる。
Ｃ：意匠外観がやや損なわれているが、パターン部と非パターン部が目視で区別できる。
Ｄ：パターン部と非パターン部の外観品位が著しく低下しており、目視で区別できない。 [Corrosion resistance]
The test plate was cut into 150 x 70 mm and subjected to 30 cycles of accelerated corrosion test CCT in accordance with JASO-M609, and then the rust occurrence was investigated and evaluated based on the following criteria. A, B, and C were passed.
A: No rust occurs, and both patterned and non-patterned parts maintain a beautiful design appearance.
B: No rust occurred, but a very slight change in the design appearance was observed between the patterned part and the non-patterned part.
C: The design appearance is slightly impaired, but the patterned area and the non-patterned area can be visually distinguished.
D: The appearance quality of the patterned portion and the non-patterned portion is significantly degraded and cannot be visually distinguished.
表に示すように、Ｎｏ．１～Ｎｏ．４５の本発明例のＺｎ－Ａｌ－Ｍｇ系溶融めっき鋼板は、溶融めっき層の化学成分が本発明の範囲であり、アルカリ電解洗浄、超純水によるスプレー水洗、乾燥、焼鈍およびＺｎ粉の付着を行ってから溶融めっきを実施したため、溶融めっき層に、パターン部と非パターン部とが形成され、パターン部における第１領域の面積率と、非パターン部における第１領域の面積率との差の絶対値が３０％以上になった。これにより、識別性及び耐食性の両方に優れていた。
As shown in the table, No. 1~No. The Zn-Al-Mg hot-dip galvanized steel sheet of Example 45 of the present invention has a hot-dip coating layer having a chemical composition within the range of the present invention, and is subjected to alkaline electrolytic cleaning, spray washing with ultrapure water, drying, annealing, and adhesion of Zn powder. Because hot-dip plating was performed after performing the above, a patterned part and a non-patterned part were formed in the hot-dipped plating layer, and the difference between the area ratio of the first region in the patterned part and the area ratio of the first region in the non-patterned part was The absolute value of has become more than 30%. As a result, both identifiability and corrosion resistance were excellent.
Ｎｏ．４６の溶融めっき鋼板は、溶融めっき層のＡｌ含有量が少なかったため、パターン部における第１領域の面積率と、非パターン部における第１領域の面積率との差の絶対値が３０％未満になった。これにより、識別性及び耐食性の両方が劣位となった。
Ｎｏ．４７の溶融めっき鋼板は、溶融めっき層のＡｌ含有量が過剰であったため、６ヶ月間の屋外暴露によってパターン部が薄くなり、識別性が劣位となった。
Ｎｏ．４８の溶融めっき鋼板は、溶融めっき層のＭｇ含有量が少なかったため、６ヶ月間の屋外暴露によってパターン部が薄くなり、識別性が劣位になり、また、耐食性も低下した。
Ｎｏ．４９の溶融めっき鋼板は、溶融めっき層のＭｇ含有量が過剰であったため、識別性および耐食性が劣位になった。
Ｎｏ．５０の溶融めっき鋼板は、溶融めっき層の成分は適切であったが、Ｚｎ粉を付着させなかった。そのため、Ｎｏ．５０の溶融めっき鋼板は、パターン部における第１領域の面積率と、非パターン部における第１領域の面積率との差の絶対値が３０％未満になった。これにより、識別性および耐食性が劣位になった。
Ｎｏ．５１の溶融めっき鋼板は、溶融めっき層の成分が適切であり、また、溶融めっき処理の前に鋼板表面にＺｎ粉を付着させた。ただしＮｏ．５１の溶融めっき鋼板は、Ｚｎを付着させる前の鋼板の表面の洗浄が不十分であった。そのため、Ｎｏ．５１の溶融めっき鋼板は、パターン部における第１領域の面積率と、非パターン部における第１領域の面積率との差の絶対値が３０％未満になった。これにより、識別性が劣位となった。 No. In hot-dip-coated steel sheet No. 46, the Al content of the hot-dip-coated layer was low, so the absolute value of the difference between the area ratio of the first region in the pattern part and the area ratio of the first region in the non-pattern part was less than 30%. became. This resulted in inferiority in both identifiability and corrosion resistance.
No. In hot-dip plated steel sheet No. 47, the Al content of the hot-dip plated layer was excessive, so the pattern part became thinner after being exposed to the outdoors for 6 months, and the distinguishability was inferior.
No. In hot-dip plated steel sheet No. 48, since the Mg content in the hot-dip plated layer was low, the pattern part became thinner after being exposed to the outdoors for 6 months, and the distinguishability became inferior, and the corrosion resistance also decreased.
No. Hot-dip plated steel sheet No. 49 had an excessive Mg content in the hot-dip plated layer, so its distinguishability and corrosion resistance were inferior.
No. In the hot-dip plated steel sheet No. 50, although the hot-dip plated layer had appropriate components, no Zn powder was attached to it. Therefore, No. For the hot-dip plated steel sheet No. 50, the absolute value of the difference between the area ratio of the first region in the pattern portion and the area ratio of the first region in the non-pattern portion was less than 30%. This resulted in inferior identifiability and corrosion resistance.
No. In hot-dip-plated steel sheet No. 51, the composition of the hot-dip-plated layer was appropriate, and Zn powder was attached to the surface of the steel sheet before the hot-dip plating treatment. However, No. In hot-dip plated steel plate No. 51, the surface of the steel plate was insufficiently cleaned before Zn was attached. Therefore, No. In hot-dip plated steel sheet No. 51, the absolute value of the difference between the area ratio of the first region in the pattern part and the area ratio of the first region in the non-pattern part was less than 30%. This resulted in inferior identifiability.
Ｎｏ．４７の溶融めっき鋼板は、溶融めっき層のＡｌ含有量が過剰であったため、６ヶ月間の屋外暴露によってパターン部が薄くなり、識別性が劣位となった。
Ｎｏ．４８の溶融めっき鋼板は、溶融めっき層のＭｇ含有量が少なかったため、６ヶ月間の屋外暴露によってパターン部が薄くなり、識別性が劣位になり、また、耐食性も低下した。
Ｎｏ．４９の溶融めっき鋼板は、溶融めっき層のＭｇ含有量が過剰であったため、識別性および耐食性が劣位になった。
Ｎｏ．５０の溶融めっき鋼板は、溶融めっき層の成分は適切であったが、Ｚｎ粉を付着させなかった。そのため、Ｎｏ．５０の溶融めっき鋼板は、パターン部における第１領域の面積率と、非パターン部における第１領域の面積率との差の絶対値が３０％未満になった。これにより、識別性および耐食性が劣位になった。
Ｎｏ．５１の溶融めっき鋼板は、溶融めっき層の成分が適切であり、また、溶融めっき処理の前に鋼板表面にＺｎ粉を付着させた。ただしＮｏ．５１の溶融めっき鋼板は、Ｚｎを付着させる前の鋼板の表面の洗浄が不十分であった。そのため、Ｎｏ．５１の溶融めっき鋼板は、パターン部における第１領域の面積率と、非パターン部における第１領域の面積率との差の絶対値が３０％未満になった。これにより、識別性が劣位となった。 No. In hot-dip-coated steel sheet No. 46, the Al content of the hot-dip-coated layer was low, so the absolute value of the difference between the area ratio of the first region in the pattern part and the area ratio of the first region in the non-pattern part was less than 30%. became. This resulted in inferiority in both identifiability and corrosion resistance.
No. In hot-dip plated steel sheet No. 47, the Al content of the hot-dip plated layer was excessive, so the pattern part became thinner after being exposed to the outdoors for 6 months, and the distinguishability was inferior.
No. In hot-dip plated steel sheet No. 48, since the Mg content in the hot-dip plated layer was low, the pattern part became thinner after being exposed to the outdoors for 6 months, and the distinguishability became inferior, and the corrosion resistance also decreased.
No. Hot-dip plated steel sheet No. 49 had an excessive Mg content in the hot-dip plated layer, so its distinguishability and corrosion resistance were inferior.
No. In the hot-dip plated steel sheet No. 50, although the hot-dip plated layer had appropriate components, no Zn powder was attached to it. Therefore, No. For the hot-dip plated steel sheet No. 50, the absolute value of the difference between the area ratio of the first region in the pattern portion and the area ratio of the first region in the non-pattern portion was less than 30%. This resulted in inferior identifiability and corrosion resistance.
No. In hot-dip-plated steel sheet No. 51, the composition of the hot-dip-plated layer was appropriate, and Zn powder was attached to the surface of the steel sheet before the hot-dip plating treatment. However, No. In hot-dip plated steel plate No. 51, the surface of the steel plate was insufficiently cleaned before Zn was attached. Therefore, No. In hot-dip plated steel sheet No. 51, the absolute value of the difference between the area ratio of the first region in the pattern part and the area ratio of the first region in the non-pattern part was less than 30%. This resulted in inferior identifiability.
インクジェット法で正方形状のパターン部を印刷したＮｏ．５２は、６ヶ月間の屋外暴露によってパターン部が薄くなり、識別性が低下した。
また、研削によって正方形状のパターンを形成したＮｏ．５３は、研削した箇所のめっき層の厚みが低下し、研削箇所での耐食性が低下した。 No. 2, in which a square pattern was printed using the inkjet method. In No. 52, the pattern portion became thinner due to outdoor exposure for 6 months, and the distinguishability decreased.
In addition, No. 1, in which a square pattern was formed by grinding. In No. 53, the thickness of the plating layer at the ground location decreased, and the corrosion resistance at the ground location decreased.
また、研削によって正方形状のパターンを形成したＮｏ．５３は、研削した箇所のめっき層の厚みが低下し、研削箇所での耐食性が低下した。 No. 2, in which a square pattern was printed using the inkjet method. In No. 52, the pattern portion became thinner due to outdoor exposure for 6 months, and the distinguishability decreased.
In addition, No. 1, in which a square pattern was formed by grinding. In No. 53, the thickness of the plating layer at the ground location decreased, and the corrosion resistance at the ground location decreased.
１…鋼板
２…溶融めっき層
２ａ…溶融めっき層の表面
２１…パターン部
２２…非パターン部
３…ｔ／４位置における断面
４…ｔ／２位置における断面
５…３ｔ／４位置における断面
Ａ１…第１領域
Ａ２…第２領域 1...Steel plate 2... Hot-dip plating layer 2a... Surface 21 of hot-dip plating layer... Pattern portion 22... Non-pattern portion 3... Cross section at t/4 position 4... Cross section at t/2 position 5... Cross section A1 at 3 t/4 position... First area A2...Second area
２…溶融めっき層
２ａ…溶融めっき層の表面
２１…パターン部
２２…非パターン部
３…ｔ／４位置における断面
４…ｔ／２位置における断面
５…３ｔ／４位置における断面
Ａ１…第１領域
Ａ２…第２領域 1...
Claims (6)
- 鋼板と、前記鋼板の表面に形成された溶融めっき層と、を備え、
前記溶融めっき層は、平均組成で、Ａｌ：５～２２質量％、Ｍｇ：１．０～１０質量％を含有し、残部がＺｎおよび不純物を含み、
前記溶融めっき層に、パターン部と、非パターン部とがあり、
前記パターン部及び前記非パターン部は、それぞれ、下記の測定方法で得られる第１領域、第２領域のうちの１種または２種を含み、
前記パターン部における前記第１領域の面積率と、前記非パターン部における前記第１領域の面積率との差の絶対値が、３０％以上であることを特徴とする、溶融めっき鋼板。
［測定方法］
前記溶融めっき層の厚みをｔとして、前記溶融めっき層の表面から３ｔ／４位置、ｔ／２位置またはｔ／４位置のいずれかの位置において前記表面に平行な１～５ｍｍ四方の断面を露出させ、前記の各断面に０．５ｍｍ間隔で仮想格子線を描き、前記仮想格子線によって区画される複数の領域においてそれぞれ、〔Ｚｎ相〕および〔Ａｌ／ＭｇＺｎ２／Ｚｎの三元共晶組織〕の合計面積分率Ａに対する〔Ｚｎ相〕の面積分率Ｂの比率（Ｂ／Ａ（％））が２０％以上になる領域を前記第１領域とし、比率（Ｂ／Ａ（％））が２０％未満となる領域を第２領域とする。 comprising a steel plate and a hot-dip plating layer formed on the surface of the steel plate,
The hot-dip plating layer has an average composition of Al: 5 to 22% by mass, Mg: 1.0 to 10% by mass, and the remainder contains Zn and impurities,
The hot-dip plating layer has a pattern part and a non-pattern part,
The pattern portion and the non-pattern portion each include one or two of a first region and a second region obtained by the following measurement method,
A hot-dip plated steel sheet, characterized in that the absolute value of the difference between the area ratio of the first region in the pattern part and the area ratio of the first region in the non-pattern part is 30% or more.
[Measuring method]
The thickness of the hot-dip plating layer is t, and a cross section of 1 to 5 mm square parallel to the surface is exposed at any position of 3t/4, t/2 or t/4 from the surface of the hot-dip plating layer. Then, virtual lattice lines were drawn at 0.5 mm intervals on each of the above-mentioned cross sections, and a ternary eutectic structure of [Zn phase] and [Al/MgZn 2 /Zn] was formed in a plurality of regions partitioned by the virtual lattice lines. The area where the ratio (B/A (%)) of the area fraction B of [Zn phase] to the total area fraction A of ] is 20% or more is defined as the first region, and the ratio (B/A (%)) The region where the difference is less than 20% is defined as the second region. - 鋼板と、前記鋼板の表面に形成された溶融めっき層と、を備え、
前記溶融めっき層は、平均組成で、Ａｌ：５～２２質量％、Ｍｇ：１．０～１０質量％を含有し、残部がＺｎおよび不純物を含み、
さらに下記Ａ群、Ｂ群からなる群から選択される１種または２種を含有し、
前記溶融めっき層に、パターン部と、非パターン部とがあり、
前記パターン部及び前記非パターン部は、それぞれ、下記の測定方法で得られる第１領域、第２領域のうちの１種または２種を含み、
前記パターン部における前記第１領域の面積率と、前記非パターン部における前記第１領域の面積率との差の絶対値が、３０％以上であることを特徴とする、溶融めっき鋼板。
［Ａ群］Ｓｉ：０．０００１～２質量％
［Ｂ群］Ｎｉ、Ｔｉ、Ｚｒ、Ｓｒ、Ｆｅ、Ｓｂ、Ｐｂ、Ｓｎ、Ｃａ、Ｃｏ、Ｍｎ、Ｐ、Ｂ、Ｂｉ、Ｃｒ、Ｓｃ、Ｙ、ＲＥＭ、Ｈｆ、Ｃのいずれか１種または２種以上を、合計で０．０００１～２質量％
［測定方法］
前記溶融めっき層の厚みをｔとして、前記溶融めっき層の表面から３ｔ／４位置、ｔ／２位置またはｔ／４位置のいずれかの位置において前記表面に平行な１～５ｍｍ四方の断面を露出させ、前記の各断面に０．５ｍｍ間隔で仮想格子線を描き、前記仮想格子線によって区画される複数の領域においてそれぞれ、〔Ｚｎ相〕および〔Ａｌ／ＭｇＺｎ２／Ｚｎの三元共晶組織〕の合計面積分率Ａに対する〔Ｚｎ相〕の面積分率Ｂの比率（Ｂ／Ａ（％））が２０％以上になる領域を前記第１領域とし、比率（Ｂ／Ａ（％））が２０％未満となる領域を第２領域とする。 comprising a steel plate and a hot-dip plating layer formed on the surface of the steel plate,
The hot-dip plating layer has an average composition of Al: 5 to 22% by mass, Mg: 1.0 to 10% by mass, and the remainder contains Zn and impurities,
Furthermore, it contains one or two selected from the group consisting of Group A and Group B below,
The hot-dip plating layer has a pattern part and a non-pattern part,
The pattern portion and the non-pattern portion each include one or two of a first region and a second region obtained by the following measurement method,
A hot-dip plated steel sheet, characterized in that the absolute value of the difference between the area ratio of the first region in the pattern part and the area ratio of the first region in the non-pattern part is 30% or more.
[Group A] Si: 0.0001 to 2% by mass
[Group B] Any one or two of Ni, Ti, Zr, Sr, Fe, Sb, Pb, Sn, Ca, Co, Mn, P, B, Bi, Cr, Sc, Y, REM, Hf, and C 0.0001 to 2% by mass of seeds or more in total
[Measuring method]
The thickness of the hot-dip plating layer is t, and a cross section of 1 to 5 mm square parallel to the surface is exposed at any position of 3t/4, t/2 or t/4 from the surface of the hot-dip plating layer. Then, virtual lattice lines were drawn at 0.5 mm intervals on each of the above-mentioned cross sections, and a ternary eutectic structure of [Zn phase] and [Al/MgZn 2 /Zn] was formed in a plurality of regions partitioned by the virtual lattice lines. The area where the ratio (B/A (%)) of the area fraction B of [Zn phase] to the total area fraction A of ] is 20% or more is defined as the first region, and the ratio (B/A (%)) The region where the difference is less than 20% is defined as the second region. - 前記パターン部が、直線部、曲線部、ドット部、図形、数字、記号若しくは文字のいずれか１種またはこれらのうちの２種以上を組合せた形状となるように配置されていることを特徴とする請求項１または請求項２に記載の溶融めっき鋼板。 The pattern portion is arranged so as to have a shape of any one of a straight line portion, a curved portion, a dot portion, a figure, a number, a symbol, or a character, or a combination of two or more of these. The hot-dip plated steel sheet according to claim 1 or claim 2.
- 前記溶融めっき層の付着量が鋼板両面合計で３０～６００ｇ／ｍ２であることを特徴とする請求項１または請求項２に記載の溶融めっき鋼板。 The hot-dip plated steel sheet according to claim 1 or 2, wherein the amount of the hot-dip plated layer deposited on both sides of the steel sheet is 30 to 600 g/m 2 in total.
- 前記溶融めっき層が、質量％で、前記Ａ群を含有する平均組成を有する請求項２に記載の溶融めっき鋼板。 The hot-dip plated steel sheet according to claim 2, wherein the hot-dip plated layer has an average composition containing the group A in mass %.
- 前記溶融めっき層が、質量％で、前記Ｂ群を含有する平均組成を有する請求項２に記載の溶融めっき鋼板。 The hot-dip plated steel sheet according to claim 2, wherein the hot-dip plated layer has an average composition containing the group B in mass %.
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| JP2024503837A JP7486011B2 (en) | 2022-06-10 | 2023-06-09 | Hot-dip galvanized steel sheet |
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0860324A (en) * | 1994-08-22 | 1996-03-05 | Kawasaki Steel Corp | Zinc-magnesium-aluminum hot dip galvanized steel excellent in corrosion resistance and its production |
| JP2002241962A (en) * | 2001-02-13 | 2002-08-28 | Sumitomo Metal Ind Ltd | HOT DIP Zn-Al-Mg ALLOY PLATED STEEL SHEET AND PRODUCTION METHOD THEREFOR |
| WO2018169085A1 (en) * | 2017-03-17 | 2018-09-20 | 新日鐵住金株式会社 | Plated steel sheet |
| CN109897990A (en) * | 2019-04-28 | 2019-06-18 | 攀钢集团攀枝花钢铁研究院有限公司 | Hot-dip aluminum zinc Mg Alloy Coating steel plate and preparation method thereof |
| JP2021508779A (en) * | 2017-12-26 | 2021-03-11 | ポスコＰｏｓｃｏ | Zinc alloy plated steel with excellent corrosion resistance and surface smoothness and its manufacturing method |
| WO2021106259A1 (en) * | 2019-11-29 | 2021-06-03 | 日本製鉄株式会社 | Hot dip coated steel sheet |
-
2023
- 2023-06-09 WO PCT/JP2023/021579 patent/WO2023238941A1/en unknown
- 2023-06-09 JP JP2024503837A patent/JP7486011B2/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0860324A (en) * | 1994-08-22 | 1996-03-05 | Kawasaki Steel Corp | Zinc-magnesium-aluminum hot dip galvanized steel excellent in corrosion resistance and its production |
| JP2002241962A (en) * | 2001-02-13 | 2002-08-28 | Sumitomo Metal Ind Ltd | HOT DIP Zn-Al-Mg ALLOY PLATED STEEL SHEET AND PRODUCTION METHOD THEREFOR |
| WO2018169085A1 (en) * | 2017-03-17 | 2018-09-20 | 新日鐵住金株式会社 | Plated steel sheet |
| JP2021508779A (en) * | 2017-12-26 | 2021-03-11 | ポスコＰｏｓｃｏ | Zinc alloy plated steel with excellent corrosion resistance and surface smoothness and its manufacturing method |
| CN109897990A (en) * | 2019-04-28 | 2019-06-18 | 攀钢集团攀枝花钢铁研究院有限公司 | Hot-dip aluminum zinc Mg Alloy Coating steel plate and preparation method thereof |
| WO2021106259A1 (en) * | 2019-11-29 | 2021-06-03 | 日本製鉄株式会社 | Hot dip coated steel sheet |
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| JP7486011B2 (en) | 2024-05-17 |
| TW202405205A (en) | 2024-02-01 |
| JPWO2023238941A1 (en) | 2023-12-14 |
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